About A4M | Worldhealth.net Anti-Aging News

Established in 1991, the American Academy of Anti-Aging Medicine (A4M) is a US federally registered 501(c) 3 non-profit organization comprised of 26,000-plus member physicians, health practitioners, scientists, governmental officials, and members of the general public, representing over 120 nations.

The A4M is dedicated to the advancement of technology to detect, prevent, and treat aging related disease and to promote research into methods to retard and optimize the human aging process. The A4M is also dedicated to educating physicians, scientists, and members of the public on biomedical sciences, breaking technologies, and anti-aging issues.

The A4M believes that the disabilities associated with normal aging are caused by physiological dysfunction which in many cases are ameliorable to medical treatment, such that the human lifespan can be increased, and the quality of one's life enhanced as one grows chronologically older.

The A4M seeks to disseminate information concerning innovative science and research as well as treatment modalities designed to prolong the human lifespan. Anti-Aging Medicine is based on the scientific principles of responsible medical care consistent with those of other healthcare specialties. Although the A4M seeks to disseminate information on many types of medical treatments, it does not promote or endorse any specific treatment nor does it sell or endorse any commercial product.

The A4M is comprised of 26,000-plus members from 120 nations worldwide, as follows:

The disciplines of our physician members are roughly as follows:

Read more:
About A4M | Worldhealth.net Anti-Aging News

Guanidine – Wikipedia

Guanidine is the compound with the formula HNC(NH 2)2. It is a colourless solid that dissolves in polar solvents. It is a strong base that is used in the production of plastics and explosives. It is found in urine as a normal product of protein metabolism. Guanidine is the functional group on the side chain of arginine.

Guanidine can be thought of as a nitrogenous analogue of carbonic acid. That is, the C=O group in carbonic acid is replaced by a C=NH group, and each OH is replaced by a NH 2 group.[3] A detailed crystallographic analysis of guanidine was elucidated 148 years after its first synthesis, despite the simplicity of the molecule.[4] In 2013, the positions of the hydrogen atoms and their displacement parameters were accurately determined using single-crystal neutron diffraction.[5]

Guanidine can be obtained from natural sources, being first isolated by Adolph Strecker via the degradation of guanine.[6]

The compound was first synthesized in 1861 by the oxidative degradation of an aromatic natural product, guanine, isolated from Peruvian guano.[7] The commercial route involves a two step process starting with the reaction of dicyandiamide with ammonium salts. Via the intermediacy of biguanidine, this ammonolysis step affords salts of the guanidinium cation (see below). In the second step, the salt is treated with base, such as sodium methoxide.[6]

With a pKb of 0.4, guanidine is a strong base. In neutral water, it exists exclusively as guanidinium (C(NH 2)+ 3). Most guanidine derivatives are in fact such salts.

The main salt of commercial interest is the nitrate [C(NH 2)3]NO 3. It is used as a propellant, for example in air bags.

Guanidine is protonated in physiological conditions. This conjugate acid is called the guanidinium cation, (C(NH 2)+ 3). It is a highly stable +1 cation in aqueous solution due to the efficient resonance stabilization of the charge and efficient solvation by water molecules. As a result, its pKa is 13.6[8] meaning that guanidine is a very strong base in water.

Guanidinium chloride has chaotropic properties and is used to denature proteins. Guanidine hydrochloride is known to denature proteins with a linear relationship between concentration and free energy of unfolding. In aqueous solutions containing 6M guanidinium chloride, almost all proteins lose their entire secondary structure and become randomly coiled peptide chains. Guanidinium thiocyanate is also used for its denaturing effect on various biological samples. Guanidine hydrochloride[9] is used as an adjuvant in treatment of botulism, introduced in 1968,[10] but now its role is considered controversial[11] because in some patients there was no improvement after this drug administration.

Guanidinium hydroxide is the active ingredient in some non-lye hair relaxers.

Guanidines are a group of organic compounds sharing a common functional group with the general structure (R 1R 2N)(R 3R50 4. The central bond within this group is that of an imine, and the group is related structurally to amidines and ureas. Examples of guanidines are arginine, triazabicyclodecene, saxitoxin, and creatine.

Galegine is isoamylene guanidine.[12]

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Guanidine - Wikipedia

Integrative Medicine in Charlotte, North Carolina with …

Physicians and surgeons help to keep people - from infants to the elderly - as healthy as possible. These individuals provide diagnoses and treatments for a wide variety of ailments, and preventative care and early detection for more serious illnesses. Whether you love or hate going to the doctor, the fact is your physician is there to listen to your health concerns, take preventative measures against diseases and advise you on your optionsfor stayingin tip-top shape.

In 2013, there were more than 1 million doctors of medicine in the U.S., over 854,000 of which were active. Additionally, in 2012, there were about 18,000 active general surgeons in the country. It's important to know which type of physician or surgeon you need, how to choose the best one, and account for other considerations in order to stay healthy.

Patients can choose from a wide variety of physicians depending on doctor specialty and what problems they are experiencing. Here are a few of the most common types of physicians that you may see in your lifetime:

General Practitioner Your GP is the doctor that you go to for regular checkups, vaccines and to identify health issues. GPs can treat many different illnesses and injuries, from the common cold to a broken arm. If your health requires a second opinion or expert care, the GP will refer you to a specialist who has the skills to focus in on the issue.

Cardiologist Heart attacks and heart disease are some of the most common afflictions seen across the country, making cardiologists important to your long-term health. These physicians specialize in studying and treating the heart and related diseases.

Dentist Other than a GP, the dentist is likely the most common physician you'll ever see. These professionals work with the human mouth, ensuring that your teeth and gum health are up to par. Patients typically go to the dentist twice a year.

Dermatologist Dermatologists are focused on skin-related issues and diseases, from skin cancers, to acute acne, eczema, psoriasis, and general cosmetic concerns like aging and scars. Most will also perform annual or semi-annual mole checks to screen for any signs of melanoma, the most serious form of skin cancer.

ENT If you have a number of sinus infections or have had your tonsils taken out, you've likely seen an ENT specialist. ENTs handle ailments related to the ear, nose and throat, often related to taking out tonsils and treating hearing issues.

OB/GYN For many women, their gynecologist and obstetrician are the same person. These professionals work with the female reproductive system to focus on reproductive health, fertility issues, prenatal care, options for new and expectant mothers, neonatal care and childbirth. OB/GYNs can also help in the early detection of breast or cervical cancer.

There are obviously a number of physicians that you can choose from, but how do you know if they'rethe best choice for you? Here are a few considerations to help you pick a physician:

Look at Your Insurance Before you get down to the details, you need to verify which doctors are covered by your insurance and whether they are in or out of your carrier's network. Rates may be cheaper if the doc is in network a doctor can be covered by your insurance but not necessarily in network. Out of network is typically more expensive.Doctors often add and drop plans, so it's important to ensure that your options are compatible with your insurance plan. Doing your homework will help you avoid unexpected expenses.

Check for Board Certification Your physician should be certified through the American Board of Medical Specialties. Doctors must earn a medical degree from a qualified school, complete three to seven years of residency training, be licensed by a state medical board and pass one or more ABMS exams to be certified.

Examine the Reviews Reviewsof a doctor can reveal a lot about what your experience may be like. People may grade on staff friendliness, availability and effectiveness of treatment. Looking at these evaluations and getting recommendations from family and friends can direct you toward a physician for your needs.

Surgeons can literally hold your life in their hands, and it's important to find the best one that can put you at ease and treat you effectively

Compatibility Factor You need to feel comfortable with your surgeon. It's important to communicate your concerns and that your surgeon can respond adequately. Surgeons should be willing to go over the details of your procedure and answer any questions that you may have. They must take the time to discuss and address your worries.

Expertise Level If you're going in for surgery, you want someone that knows what they're doing and has a high success rate. Ask how often the surgeon performs this surgery and try to find one that regularly does it. This will give you peace of mind that you're in capable hands.

Your decisionon a physician or surgeon can be majorly affected by the insurance plan you have. You may have insurance through employment, your spouse, your parents if you're under 26, or the marketplace if the previous options don't apply to you. It's important to understand how your insurance works to have the full picture of what you'll need to pay for.

Your insurance will have a deductible, which is the amount that you're responsible to pay for covered medical expenses. Some plans have coinsurances, where you must pay a certain percentage of the bill, and insurance will cover the rest. Co-pays state a flat rate for certain services, like paying $20 when you visit your GP or a $100 co-pay for an emergency room visit. Once you reach your out-of-pocket maximum, which will differ if you're an individual or within a family plan, your insurance may pay for 100 percent of covered medical expenses for the rest of the plan year.

If youplan to go to the doctor, need medication or have been recommended for surgery, call your insurance provider or go online to see what your plan covers. You can choose the best doctor for your needs, understand your options and prevent yourself from being blindsided by medical expenses.

Most doctors require a phone call for an appointment, although some may provide online scheduling as well. Be sure to have your insurance card with you when you set an appointment, and to bring it with you to the actual appointment. They need the ID numbers to verify your coverage, and will usually make a copy of the card for their files so you don't have to show it again unless your insurance changes.

When you call, let them know if you're a new patient, as this will require you to complete some paperwork for your first visit. Tell them the reason for your visit, such as your symptoms if you're feeling sick. It's also important to inform them if you have Medicaid and to find out if you need to bring anything to the visit, like current medications or medical records.

From here, the receptionist will likely ask what dates and times work best for you. During your call, it's important to be honest about your symptoms and the reason for your visit. This information will help the doctor treat you and give him or her an idea of what to expect. Your appointment may progress faster as a result, and the doctor can come prepared with a list of options to better care for you.

Doctors see a number of patients in a day, sometimes in 15-minute increments in areas where the physicians are in high demand. This can leavelittle time for doctors to perform thorough examinations, and they can end up missing certain problem indicators. While some problems, like a cold or flu, can be diagnosedin this time, more complex ailments require attention, which takes up time. Reviews can illuminate which doctors actively spend the necessary time with their patients and which ones are pressed against the clock to meet demand.

Surgery has some more dire risks attached to it, so be sure to talk to your surgeon about the potential issues that can come up as a result of your procedure. If a patient has a reaction to anesthesia, it can cause very serious complications, but this is an uncommon occurrence. Blood clots can be a significant problem aftersurgery, often caused by inactivity during recovery. Infections, numbness, scarring, swelling and death are all possible, but the likelihood of these issueswill vary depending on the type of surgery you're undergoing. Talk to your doctor about your concerns and your risk potential.

Surgery affects people in different ways, but as you begin to emerge from anesthesia, you'll want to alert your nurse to any issues you may have. The nurse will tell you how the procedure went, what effect it will have on your condition, what to expect when you get home and how long it will take to getback to normal. If you start feeling pain, the nurse may give you medication to stop it from getting worse. When possible, it's also advised to move around to avoid blood clots from developing in your legs. This can be as simple as occasionally flexing your knee or rotating your foot.

Some surgeries are outpatient procedures, where people are released the same day. For major surgeries, patients may stay at the hospital for a few days to be monitored and address any concerns before being sent home. Discuss with your surgeon the projected length of the hospital stayand what you need to bring.

Your recovery time and follow-up expectations will vary depending on your procedure. For example, you can be expected to be on your feet within a few days of having your wisdom teeth taken out, but it may be weeks before you have fully recovered from a broken foot or heart-valve surgery. Your surgeon will give you a list of things that you'll need to do during this time, including what medications to take and when you'll be able to get back to work and other activities.

Every surgery will have a follow-up call or appointment to discuss your recovery and allow you to ask any questions about unusual symptoms or changes in your overall health. If you have a major operation, like heart surgery, it's important to make regular checkupswith your doctor or a specialist to ensure that everything is normal. Visiting a doctor will help deter infection and verify that everything is healing as expected. These appointments will give you peace of mind about your state of health and ensure that any issues are caught early on.

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Integrative Medicine in Charlotte, North Carolina with ...

Family Practice & more in Denver, NC

The physicians and staff of North State Medical Group, P.A. would like to thank you for choosing us to meet your medical needs. Our website should help answer any questions you may have about our practice.

Our commitment is to consistently provide the highest quality and most up-to-date care possible. It is our goal to provide comprehensive care to your entire family. If a health problem should arise that fall outside our specialty, we will assist you in locating an appropriate specialist and work closely with them to ensure your complete satisfaction.

We offer two locations for your convenience. To schedule an appointment at one of our offices, please see the phone numbers below or visit our Locations page.

or fill in the form on our Appointments page:

FILL IN THE FORM

Our most important medical departments, but just a few of what our clinic offers:

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Dr. Gerald Ahigian and Dr. Susane Habashi-Ahigian

To learn more about our team of physicians, please click the button below.

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These doctors have taken care of my in-laws for about fifteen years and my in laws, and now we, love them. Doctors Susane and Gerald are always glad to take all the time I need to discuss anything that I feel is important. They have listened to my side of the story, and what I think is wrong with me and they do not immediately discredit my ability to judge my problem. . . .They do not rush their patients in and out. If I have to wait longer than 20 minutes, it is rare, but I dont care because I know that I will receive the same lengthy, courteous, professional treatment.

K Douthit

This is a wonderful place to receive care from. The doctors and nurses are very compassionate and make you feel very comfortable.

Melinda

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Family Practice & more in Denver, NC

About A4M | Worldhealth.net Anti-Aging News

Established in 1991, the American Academy of Anti-Aging Medicine (A4M) is a US federally registered 501(c) 3 non-profit organization comprised of 26,000-plus member physicians, health practitioners, scientists, governmental officials, and members of the general public, representing over 120 nations.

The A4M is dedicated to the advancement of technology to detect, prevent, and treat aging related disease and to promote research into methods to retard and optimize the human aging process. The A4M is also dedicated to educating physicians, scientists, and members of the public on biomedical sciences, breaking technologies, and anti-aging issues.

The A4M believes that the disabilities associated with normal aging are caused by physiological dysfunction which in many cases are ameliorable to medical treatment, such that the human lifespan can be increased, and the quality of one's life enhanced as one grows chronologically older.

The A4M seeks to disseminate information concerning innovative science and research as well as treatment modalities designed to prolong the human lifespan. Anti-Aging Medicine is based on the scientific principles of responsible medical care consistent with those of other healthcare specialties. Although the A4M seeks to disseminate information on many types of medical treatments, it does not promote or endorse any specific treatment nor does it sell or endorse any commercial product.

The A4M is comprised of 26,000-plus members from 120 nations worldwide, as follows:

The disciplines of our physician members are roughly as follows:

Original post:
About A4M | Worldhealth.net Anti-Aging News

BioTexCom Center for Human Reproduction in Ukraine, Kiev

For many years, Center for Human Reproduction BioTexCom has been successfully conducting and improving programs of surrogate motherhood and egg donation for infertile couples from around the world. BioTexCom medical center is familiar to everybody it knocks people socks with great results, kindles international medias interest, and year by year keeps leading ground in the reproductive medicine field. BioTexCom is a perfect combination of professional team, certified talented doctors, Ukrainian hospitality and high success rate of medical programs. Our doctors develop the most effective methods of infertility treatment and achieve successful results conducting minimum number of IVF attempts.

Much of BioTexCom clinic is owed to famous Ukrainian embryologist, geneticist and just a talented scientist, Yury Verlinsky. He was one of the first in the world who introduced pre-implantation genetic diagnosis (PGD), which is so popular in modern reproductive medicine. It was he who initiated PGD use for the hereditary diseases prevention. Due to Yury Verlinskys developments, today BioTexCom center has an opportunity to conduct IVF programs for aged women, excluding all health risks and fetal abnormalities.

History of our clinic has a great records page as well. In 2012, Swiss woman appealed for help to the BioTexCom clinic and went through the IVF program with donor eggs. As a result, 66-year-old woman successfully gave birth to healthy twins. Visiting our reproductive center women of 40, 50, 60 years are successfully carried out such programs as IVF, surrogate motherhood, egg donation. Center for Human Reproduction BioTexCom received an award for the best service (Customer Service Award). Managers who help foreign patients during the program are fluent in different languages : English, German, Italian, French, Romanian, Hebrew and Chinese. BioTexCom is the only clinic of reproductive medicine in Europe, where clients are offered the most favorable conditions and 100% guarantee.

BioTexCom Medical Center was founded in the capital of Ukraine, Kiev, by a German citizen Mr. Albert Totchilovsky. He has gathered rich European experience and combined it with unique skills of Ukrainian specialists. Doctors of BioTexCom center deal even with the most hopeless cases of infertility. Over clinics history of work, it gives the good of long-awaited happiness of motherhood and fatherhood to thousands of infertile couples from around the world. After numerous failed IVF attempts, they go to Ukraine, because there is no absolute infertility for BioTexCom specialists!

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BioTexCom Center for Human Reproduction in Ukraine, Kiev

The Visible Body Blog

Well, here we are again in the final stretch of the year. Hard to believe 2016 is over, huh? Although I won't be sad to say goodbye to itCarrie Fisher, Debbie Reynolds, and George Michael, all in less than a week? 2016 had no chill.

Despite the fact that this year's Oscar In Memoriam segment is going to be 45 minutes long, 2016 also had its bright moments: it had some of the wackiest, most incredible happenings in the world of medicine.

Let's take a look at some of 2016's coolest medical stories:

Why not kick off with my favorite story from this year, which involved a woman undergoing surgery and waking up with an accent that wasn't the one she had when she went under. When I first read this back in June, I was skeptical. If anything, this woman had to be pulling a Madonna, right?

Wrong.

When she had surgery to correct her overbite, Lisa Alamia, a born-and-bred American, came out of it speaking with a completely different accenta British one. Well, sort of. She woke up with the incredibly rare condition known as Foreign Accent Syndrome. There are only 100 known cases of it, with most resulting from neurological damage or head trauma, although Alamia's scans and tests have all come back clear.

FAS occurs when the part of the brain that deals with the actual vocals of speech (cadence, melody, rhythm, etc.) is damaged, and speech is altered in terms of timing, intonation, and tongue placement so that is perceived as sounding foreign, resulting in a new "accent." It's important to note that Alamia isn't technically speaking with a British accent; the cadence of her speech has changed to sound like it (especially to Americans like me).

According to the University of Texas at Dallas, FAS has been documented in cases around the world, including accent changes from Japanese to Korean, British English to French, American-English to British English, and Spanish to Hungarian.

So while Lisa Alamia might not be firing up the tea kettle and having bangers and mash on the regular, her new "accent" is still super cool.

Way back toward the start of the year, a tiny Windows logo wannabe came out of Vanderbilt University in Tennessee and told the world we were approaching the day when dialysis would be a thing of the past.

Bill Gates is gonna sue someone. (Vanderbilt University)

Using silicon nanotech, Vanderbilt University Medical Centers Dr. William Fissell and his team have created a filter chip that will, with the help of living kidney cells, mimic the functionality of a healthy kidney. The promised result is that it'll be about the size of a natural kidney and will be powered by the body's own blood flow.

What's incredible about this little filter is the aforementioned kidney cells, which do things like nutrient reabsorption and getting rid of accumulated wastesomething that synthetic components aren't good at.

Wanna learn more about it? Check it out here:

It seems almost too good to be true. Chocolate is, after all, a sugar and high fat bomb that can cause obesity and tooth decay (or an allergic reaction in my case, womp womp), so how can it be possible that eating chocolate on the reg can yield such happy results? Well, it seems through more and more focused study that moderate consumption of the confectionparticularly dark chocolateis a good thing!

I've singled out dark chocolate because it has the highest cocoa content, which means it has the highest levels of antioxidantsflavonoids, which are molecules that can prevent some forms of cell damage.

Prof. Saverio Stranges of the University of Warwick Medical School, United Kingdom and the Department of Population Health at the Luxembourg Institute of Health (LIH) and his colleagues ran the Observation of Cardiovascular Risk in Luxembourg (ORISCAV-LUX) study, which took a look at the chocolate consumption of 1,153 people between the ages of 18 and 69. The purpose of the study was to investigate whether chocolate intake is associated with insulin resistance (where the body's cells do not effectively respond to insulin, raising the risk for type 2 diabetes and heart disease), as well as how chocolate consumption affected liver enzyme levels (a measure of liver function).

Of the participants, 81.8 percent consumed chocolate, with an average consumption of 24.8 grams daily. Compared with the participants who didn't eat chocolate, those who did had reduced insulin resistance and improved liver enzyme levels. And the more chocolate consumed, the stronger the effect.

The team published their results of their study in the British Journal of Nutrition.

So continue eating that chocolate, you chocoholics! But, you know, keep exercising and brushing your teeth too.

And right on the heels of the chocolate story...

I have to admit, I've never had a cavity in my life. I'm a freak when it comes to my teeth. My most prized possession in my bag isn't my wallet, but my giant thing of dental floss, which gets used at least 5 times a day. But while I might be super vigilant about my teeth, there are plenty of those who aren't. I had friends in grade school who practically lived at the dentist's.

But cavities may be fighting a losing battle with the advent of silver diamine fluoride, or SDF. This special liquid has been in use for decades in Japan but has only recently been introduced to the States. Used as a desensitizer for adults, studies have shown that it can halt the progression of cavities and even prevent them altogether!

SDF is a microbial liquid that is painlessly brushed onto the teeth in less than a minuteno drills, no mess.

While SDF has an amazing effect on cavities, the same can't be said for what it does to the aesthetic of a tooth, or a patient's wallet. SDF darkens the brownish decay on a tooth, which can be unsightly for some and not worth the risk. Not to mention that until more insurers hop on the bandwagon, it's an out-of-pocket expense. Relatively cheap one, though, clocking in at $25 per treatment.

So, if you're prone to cavities and want to ditch the drill, you've got options!

Okay, now we need to take this with some caution, as the findings haven't been published in a peer-reviewed journal yet, but Dr. Stanley Riddell, an immunotherapy researcher and oncologist at Seattle's Fred Hutchinson Cancer Research Center, presented new adoptive T-cell strategies for cancer at the annual meeting of the American Association for the Advancement of Science in Washington, D.C. on February 14th.

One of the new strategies is a therapy that uses white T-cells as, well, attack dogs. White blood cells are extracted from terminally ill cancer patients and then genetically reprogrammed to target cancer cells. The souped-up cells are then reintroduced into a patients bloodstream, where they make it much harder for the cancer to spread and take hold.

Riddell and his colleagues have seen "sustained regression" in many relapsing and treatment-resistant cases of B-cell malignancies: acute lymphoblastic leukemia, Non-Hodgkin lymphoma and chronic lymphocytic leukemia.

In one trial, 94 percent of terminally ill lymphoblastic leukemia patients went into remission, while patients with similar blood cancers experienced response rates greater than 80 percent, with more than half going into remission.

In November of this year, Riddell received the American Cancer Society research professorship to continue his immunotherapy research.

Mosquitos are the absolute worstlike, why are they even here? All they do is suck your blood and kill over 750,000 people a year. That's not an exaggerated number, either. Mosquitos are the deadliest animals on the planet, with their bite transmitting countless diseases. Mosquito-borne Malaria alone kills 600,000 every year. If humans didn't taste so damn good to mosquitos, think of how many lives could be saved.

Well, we're working on it. And by "we" I mean "researchers at Johns Hopk
ins."

They posit that because mosquitos use a bunch of different senses (smell, temperature, and sight, among others) to detect their next human host, identifying a substance that makes the taste of humans "repulsive" to the Anopheles gambiae, or malaria mosquito, could stop the transmission of the disease.

What a jerk. (J. Gathany / Public Health Image Library)

"Our goal is to let the mosquitoes tell us what smells they find repulsive and use those to keep them from biting us," said Christopher Potter, Ph.D., assistant professor of neuroscience at the Johns Hopkins University School of Medicine.

The team isolated a special area of the mosquito brain to see where olfactory neurons went using a powerful genetic techniquenever before accomplished in mosquitoes, according to Potterto make certain neurons "glow" green. The green glowing label was designed to appear specifically in neurons that receive complex odors through proteins called odorant receptors (ORs), since OR neurons are known to help distinguish humans from other warm-blooded animals in Aedes aegypti mosquitoes, which carry the Zika virus.

Wed like to figure out what regions and neurons in the brain lead to this combined effect, said Potter. If we can identify them, perhaps we could also stop them from working.

And last but not least on our list is an interesting study out of Denmark that found pregnant women who took fish oil pills in the later stages of their pregnancies saw lower rates of Asthma in their children. The study randomly assigned 736 pregnant women at 24 weeks of gestation, and a total of 695 children were born and 95.5% completed the 3-year, double-blind follow-up period.

Among children whose mothers took fish-oil capsules, 16.9 percent had asthma by age 3, compared with 23.7 percent whose mothers were given placebos. The difference is a risk reduction of about 31 percent. Pretty significant, right?

Well, pump the breaks before any of you pregnant readers rush out to the nearest vitamin store.

The author of the study, Dr. Hans Bisgaard, professor of pediatrics at the University of Copenhagen and the head of research at the Copenhagen Prospective Studies on Asthma in Childhood, says he isn't ready to recommend that pregnant women routinely take fish oil. While the study found no adverse effects in the mothers or babies, the doses were super high: 2.4 grams per day15 to 20 times what most Americans consume from foods.

According to the Centers for Disease Control and Prevention (CDC), asthma has more than doubled in developed countries in recent decades. More than six million children in the United States have it, as do more than 330 million children and adults worldwide.

Previous research had suggested that fish oil might help prevent asthma. Since inflammation in the airways and lungs plays a major role in asthma, and fatty acids in fish oil are thought to prevent inflammation, it seems like a no-brainer. We'll have to wait and see what further studies determine.

*****

From everyone at Visible Body, we hope you had a wonderful year with us, and we look forward to bringing you more anatomy goodness in 2017.

Happy New Year!

Read more here:
The Visible Body Blog

Behavioral Science | The University of Chicago Booth School …

Behavioral Science involves research on how people make judgments and decisions, and how they interact with one another. Research in this area draws on theory and methods from cognitive and social psychology, economics, and other related fields. Behavioral Science applies these disciplines to study human behavior in a wide range of managerial and organizational contexts. Examples include:

Students focus their studies on the subset of research topics that best fit their interests and career goals and augment their studies with work in one of several support areas, which include:

Further, studies in Behavioral Science can be paired with studies in Marketing for a focus on consumer behavior, with Finance for a focus on financial decision making, and with many other scholarly fields. In addition to courses offered at Chicago Booth, students take courses in Psychology, Economics, Sociology, Public Policy, and other university departments.

The Behavioral Science program also offers theJoint Program in Psychology and Business,which is run jointly by the behavioral science dissertation area at Chicago Booth and theDepartment of Psychology in the Division of theSocial Sciences at the University of Chicago.

For more details about the PhD Program in behavioral science at Chicago Booth, see General Examination Requirements - By Area in the PhD Program Guidebook (PDF).

To learn more about the research being done by current PhD students, please view alisting of proposals and defenses across dissertation areas.

Meet the Faculty Explore research interests, publications, and course offerings of Behavioral Science Dissertation Area faculty.

Christopher Bryan Assistant Professor of Behavioral Science and FMC Faculty Scholar

Research Interests: Psychological influence, behavioral decision-making, and political psychology with a particular interest in psychology as it relates to social and public policy Faculty Profile

Eugene Caruso Associate Professor of Behavioral Science

Research Interests: Social judgment, group decision making and negotiation, egocentrism, perspective taking, and ethics Faculty Profile | Personal Website

Nicholas Epley John Templeton Keller Professor of Behavioral Science and Neubauer Family Faculty Fellow

Research Interests: The experimental study of social cognition, perspective-taking, and intuitive human judgment Faculty Profile | Personal Website

Ayelet Fishbach Jeffrey Breakenridge Keller Professor of Behavioral Science and Marketing

Research Interests: Social psychology, with specific emphasis on motivation, emotion, and decision making Faculty Profile | Personal Website

Reid Hastie Ralph and Dorothy Keller Distinguished Service Professor of Behavioral Science

Research Interests: Judgment and decision making (managerial, legal, medical, engineering, and personal), memory and cognition, and social psychology Faculty Profile

Christopher Hsee Theodore O. Yntema Professor of Behavioral Science and Marketing

Research Interests: The interplay among psychology and economics, happiness, marketing, and cross-cultural psychology Faculty Profile | Personal Website

Emma Levine Assistant Professor of Behavioral Science

Research Interests:Interpersonal trust and ethical decision-making; the tension between honesty and benevolence. Faculty Profile

Ann McGill Sears Roebuck Professor of General Management, Marketing, and Behavioral Science

Research Interests: Consumer and manager decision making, with special emphasis on causal explanations, differences in judgments in public and private, and the use of imagery in product choice Faculty Profile

Ed O'Brien Assistant Professor of Behavioral Science

Research Interests: Social cognition and hedonic processes Faculty Profile | Personal Website

Devin Pope Professor of Behavioral Science and Robert King Steel Faculty Fellow

Research Interests: Behavioral economics, with special interest in empirically testing the impact of psychological biases in economic markets Faculty Profile | Personal Website

Jane Risen Associate Professor of Behavioral Science

Research Interests: Judgment and decision making, belief formation, magical thinking, stereotyping and prejudice, and managing emotion Faculty Profile | Personal Website

Anuj Shah Associate Professor of Behavioral Science and Neubauer Family Faculty Fellow

Research Interests: How decision makers deal with limited resources Faculty Profile | Personal Website

Thomas Talhelm Assistant Professor of Behavioral Science

Research Interests: How culture affects the way we behave Faculty Profile

Richard Thaler Charles R. Walgreen Distinguished Service Professor of Behavioral Science and Economics Economics Faculty Director, Center for Decision Research

Research Interests: Behavioral economics and finance; the psychology of decision making Faculty Profile | Personal Website

Bernd Wittenbrink Robert S. Hamada Professor of Behavioral Science

Research Interests: Experimental social psychology, specifically the influence of stereotypes on social judgments Faculty Profile | Personal Website

George Wu John P. and Lillian A. Gould Professor of Behavioral Science

Research Interests: The psychology of individual, managerial, and organizational decision making; decision analysis; and cognitive biases in bargaining and negotiation Faculty Profile | Personal Website

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Behavioral Science | The University of Chicago Booth School ...

Masters in Biotechnology Programs and … – Masters PhD Degrees

Considering a Masters in Biotechnology Program or reviewing options for Masters Degrees in Biotechnology? A Masters in Biotechnology can openupexciting

Biotechnology is a challenging field that can involve a number of facets of both science and business or law. Many biotechnology master's degree programs focus on aspects of biology, cell biology, chemistry, or biological or chemical engineering. In general, biotechnology degrees involve research whether they are at a Masters or PhD level.

Scientific understanding is rapidly evolving, particularly in areas of cellular and molecular systems. Biotechnology master's students can therefore enjoy rich study opportunities particularly in fields such as genetic engineering, the Human Genome project, the production of new medicinal products, and research into the relationship between genetic malfunction and the origin of disease. These are just a few of the many areas that biotechnology students have the opportunity to explore today.

Another focus of biotechnology masters programs may be to equip students with the combination of science and business knowledge they need to help produce products and move them toward production. Today's complex business environment and government regulations require many steps and people with the ability to both understand and help produce new scientific technologies as well as get them approved and be able to market them.

Master degrees in biotechnology might prepare students to pursue careers in a variety of industries. While many students go on to further research or academic positions, there may also be some demand for biotechnologists outside of academia, both in the government and private sectors. Biotechnologists might pursue careers in anything from research to applied science and manufacturing. Those with specializations in business aspects of biotechnology may be qualified to pursue management positions within organizations attempting to produce and market new biotechnology.

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Masters in Biotechnology Programs and ... - Masters PhD Degrees

Genetically modified food – Wikipedia

Genetically modified foods or GM foods, also known as genetically engineered foods, are foods produced from organisms that have had changes introduced into their DNA using the methods of genetic engineering. Genetic engineering techniques allow for the introduction of new traits as well as greater control over traits than previous methods such as selective breeding and mutation breeding.[1]

Commercial sale of genetically modified foods began in 1994, when Calgene first marketed its unsuccessful Flavr Savr delayed-ripening tomato.[2][3] Most food modifications have primarily focused on cash crops in high demand by farmers such as soybean, corn, canola, and cotton. Genetically modified crops have been engineered for resistance to pathogens and herbicides and for better nutrient profiles. GM livestock have been developed, although as of November 2013 none were on the market.[4]

There is a scientific consensus[5][6][7][8] that currently available food derived from GM crops poses no greater risk to human health than conventional food,[9][10][11][12][13] but that each GM food needs to be tested on a case-by-case basis before introduction.[14][15][16] Nonetheless, members of the public are much less likely than scientists to perceive GM foods as safe.[17][18][19][20] The legal and regulatory status of GM foods varies by country, with some nations banning or restricting them, and others permitting them with widely differing degrees of regulation.[21][22][23][24]

However, there are ongoing public concerns related to food safety, regulation, labelling, environmental impact, research methods, and the fact that some GM seeds are subject to intellectual property rights owned by corporations.[25]

Genetically modified foods, GM foods or genetically engineered foods, are foods produced from organisms that have had changes introduced into their DNA using the methods of genetic engineering as opposed to traditional cross breeding.[26][27] In the US, the Department of Agriculture (USDA) and the Food and Drug Administration (FDA) favor the use of "genetic engineering" over "genetic modification" as the more precise term; the USDA defines genetic modification to include "genetic engineering or other more traditional methods."[28][29]

According to the World Health Organization, "Genetically modified organisms (GMOs) can be defined as organisms (i.e. plants, animals or microorganisms) in which the genetic material (DNA) has been altered in a way that does not occur naturally by mating and/or natural recombination. The technology is often called 'modern biotechnology' or 'gene technology', sometimes also 'recombinant DNA technology' or 'genetic engineering'. ... Foods produced from or using GM organisms are often referred to as GM foods."[26]

Human-directed genetic manipulation of food began with the domestication of plants and animals through artificial selection at about 10,500 to 10,100 BC.[30]:1 The process of selective breeding, in which organisms with desired traits (and thus with the desired genes) are used to breed the next generation and organisms lacking the trait are not bred, is a precursor to the modern concept of genetic modification (GM).[30]:1[31]:1 With the discovery of DNA in the early 1900s and various advancements in genetic techniques through the 1970s[32] it became possible to directly alter the DNA and genes within food.

The first genetically modified plant was produced in 1983, using an antibiotic-resistant tobacco plant.[33] Genetically modified microbial enzymes were the first application of genetically modified organisms in food production and were approved in 1988 by the US Food and Drug Administration.[34] In the early 1990s, recombinant chymosin was approved for use in several countries.[34][35] Cheese had typically been made using the enzyme complex rennet that had been extracted from cows' stomach lining. Scientists modified bacteria to produce chymosin, which was also able to clot milk, resulting in cheese curds.[36]

The first genetically modified food approved for release was the Flavr Savr tomato in 1994.[2] Developed by Calgene, it was engineered to have a longer shelf life by inserting an antisense gene that delayed ripening.[37] China was the first country to commercialize a transgenic crop in 1993 with the introduction of virus-resistant tobacco.[38] In 1995, Bacillus thuringiensis (Bt) Potato was approved for cultivation, making it the first pesticide producing crop to be approved in the USA.[39] Other genetically modified crops receiving marketing approval in 1995 were: canola with modified oil composition, Bt maize, cotton resistant to the herbicide bromoxynil, Bt cotton, glyphosate-tolerant soybeans, virus-resistant squash, and another delayed ripening tomato.[2]

With the creation of golden rice in 2000, scientists had genetically modified food to increase its nutrient value for the first time.[40]

By 2010, 29 countries had planted commercialized biotech crops and a further 31 countries had granted regulatory approval for transgenic crops to be imported.[41] The US was the leading country in the production of GM foods in 2011, with twenty-five GM crops having received regulatory approval.[42] In 2015, 92% of corn, 94% of soybeans, and 94% of cotton produced in the US were genetically modified strains.[43]

The first genetically modified animal to be approved for food use was AquAdvantage salmon in 2015.[44] The salmon were transformed with a growth hormone-regulating gene from a Pacific Chinook salmon and a promoter from an ocean pout enabling it to grow year-round instead of only during spring and summer.[45]

In April 2016, a white button mushroom (Agaricus bisporus) modified using the CRISPR technique received de facto approval in the United States, after the USDA said it would not have to go through the agency's regulatory process. The agency considers the mushroom exempt because the editing process did not involve the introduction of foreign DNA.[46]

The most widely planted GMOs are designed to tolerate herbicides. By 2006 some weed populations had evolved to tolerate some of the same herbicides. Palmer amaranth is a weed that competes with cotton. A native of the southwestern US, it traveled east and was first found resistant to glyphosate in 2006, less than 10 years after GM cotton was introduced.[47][48][49]

Genetically engineered organisms are generated and tested in the laboratory for desired qualities. The most common modification is to add one or more genes to an organism's genome. Less commonly, genes are removed or their expression is increased or silenced or the number of copies of a gene is increased or decreased.

Once satisfactory strains are produced, the producer applies for regulatory approval to field-test them, called a "field release." Field-testing involves cultivating the plants on farm fields or growing animals in a controlled environment. If these field tests are successful, the producer applies for regulatory approval to grow and market the crop. Once approved, specimens (seeds, cuttings, breeding pairs, etc.) are cultivated and sold to farmers. The farmers cultivate and market the new strain. In some cases, the approval covers marketing but not cultivation.

According to the USDA, the number of field releases for genetically engineered organisms has grown from four in 1985 to an average of about 800 per year. Cumulatively, more than 17,000 releases had been approved through September 2013.[50]

Papaya was genetically modified to resist the ringspot virus. 'SunUp' is a transgenic red-fleshed Sunset papaya cultivar that is homozygous for the coat protein gene PRSV; 'Rainbow' is a yellow-fleshed F1 hybrid developed by crossing 'SunUp' and nontransgenic yellow-fleshed 'Kapoho'.[51] The New York Times stated, "in the early 1990s, Hawaiis papaya industry was facing disaster because of the deadly papaya ringspot virus. Its single-handed savior was a breed engineered to be resistant to the virus. Without it, the states papaya industry would have collapsed. Today, 80% of Hawaiian papaya is genetically engineered, and there is still no conventional or organic method to control ringspot virus."[52] The GM cultivar was approved in 1998.[53] In China, a transgenic PRSV-resistant papaya was developed by South China Agricultural University and was first approved for commercial planting in 2006; as of 2012 95% of the papaya grown in Guangdong province and 40% of the papaya grown in Hainan province was genetically modified.[54]

The New Leaf potato, a GM food developed using naturally occurring bacteria found in the soil known as Bacillus thuringiensis (Bt), was made to provide in-plant protection from the yield-robbing Colorado potato beetle.[55] The New Leaf potato, brought to market by Monsanto in the late 1990s, was developed for the fast food market. It was withdrawn in 2001 after retailers rejected it and food processors ran into export problems.[56]

As of 2005, about 13% of the Zucchini (a form of squash) grown in the US was genetically modified to resist three viruses; that strain is also grown in Canada.[57][58]

In 2011, BASF requested the European Food Safety Authority's approval for cultivation and marketing of its Fortuna potato as feed and food. The potato was made resistant to late blight by adding resistant genes blb1 and blb2 that originate from the Mexican wild potato Solanum bulbocastanum.[59][60] In February 2013, BASF withdrew its application.[61]

In 2013, the USDA approved the import of a GM pineapple that is pink in color and that "overexpresses" a gene derived from tangerines and suppress other genes, increasing production of lycopene. The plant's flowering cycle was changed to provide for more uniform growth and quality. The fruit "does not have the ability to propagate and persist in the environment once they have been harvested," according to USDA APHIS. According to Del Monte's submission, the pineapples are commercially grown in a "monoculture" that prevents seed production, as the plant's flowers aren't exposed to compatible pollen sources. Importation into Hawaii is banned for "plant sanitation" reasons.[62]

In 2014, the USDA approved a genetically modified potato developed by J.R. Simplot Company that contained ten genetic modifications that prevent bruising and produce less acrylamide when fried. The modifications eliminate specific proteins from the potatoes, via RNA interference, rather than introducing novel proteins.[63][64]

In February 2015 Arctic Apples were approved by the USDA,[65] becoming the first genetically modified apple approved for sale in the US.[66]Gene silencing is used to reduce the expression of polyphenol oxidase (PPO), thus preventing the fruit from browning.[67]

Corn used for food and ethanol has been genetically modified to tolerate various herbicides and to express a protein from Bacillus thuringiensis (Bt) that kills certain insects.[68] About 90% of the corn grown in the U.S. was genetically modified in 2010.[69] In the US in 2015, 81% of corn acreage contained the Bt trait and 89% of corn acreage contained the glyphosate-tolerant trait.[43] Corn can be processed into grits, meal and flour as an ingredient in pancakes, muffins, doughnuts, breadings and batters, as well as baby foods, meat products, cereals and some fermented products. Corn-based masa flour and masa dough are used in the production of taco shells, corn chips and tortillas.[70]

Genetically modified soybean has been modified to tolerate herbicides and produce healthier oils.[71] In 2015, 94% of soybean acreage in the U.S. was genetically modified to be glyphosate-tolerant.[43]

Starch or amylum is a polysaccharide produced by all green plants as an energy store. Pure starch is a white, tasteless and odourless powder. It consists of two types of molecules: the linear and helical amylose and the branched amylopectin. Depending on the plant, starch generally contains 20 to 25% amylose and 75 to 80% amylopectin by weight.[72]

Starch can be further modified to create modified starch for specific purposes,[73] including creation of many of the sugars in processed foods. They include:

Lecithin is a naturally occurring lipid. It can be found in egg yolks and oil-producing plants. it is an emulsifier and thus is used in many foods. Corn, soy and safflower oil are sources of lecithin, though the majority of lecithin commercially available is derived from soy.[74][75][76][pageneeded] Sufficiently processed lecithin is often undetectable with standard testing practices.[72][not in citation given] According to the FDA, no evidence shows or suggests hazard to the public when lecithin is used at common levels. Lecithin added to foods amounts to only 2 to 10 percent of the 1 to 5 g of phosphoglycerides consumed daily on average.[74][75] Nonetheless, consumer concerns about GM food extend to such products.[77][bettersourceneeded] This concern led to policy and regulatory changes in Europe in 2000,[citation needed] when Regulation (EC) 50/2000 was passed[78] which required labelling of food containing additives derived from GMOs, including lecithin.[citation needed] Because of the difficulty of detecting the origin of derivatives like lecithin with current testing practices, European regulations require those who wish to sell lecithin in Europe to employ a comprehensive system of Identity preservation (IP).[79][verification needed][80][pageneeded]

The US imports 10% of its sugar, while the remaining 90% is extracted from sugar beet and sugarcane. After deregulation in 2005, glyphosate-resistant sugar beet was extensively adopted in the United States. 95% of beet acres in the US were planted with glyphosate-resistant seed in 2011.[81] GM sugar beets are approved for cultivation in the US, Canada and Japan; the vast majority are grown in the US. GM beets are approved for import and consumption in Australia, Canada, Colombia, EU, Japan, Korea, Mexico, New Zealand, Philippines, Russian Federation and Singapore.[82] Pulp from the refining process is used as animal feed. The sugar produced from GM sugarbeets contains no DNA or proteinit is just sucrose that is chemically indistinguishable from sugar produced from non-GM sugarbeets.[72][83] Independent analyses conducted by internationally recognized laboratories found that sugar from Roundup Ready sugar beets is identical to the sugar from comparably grown conventional (non-Roundup Ready) sugar beets. And, like all sugar, sugar from Roundup Ready sugar beets contains no genetic material or detectable protein (including the protein that provides glyphosate tolerance).[84]

Most vegetable oil used in the US is produced from GM crops canola,[85]corn,[86][87]cotton[88] and soybeans.[89] Vegetable oil is sold directly to consumers as cooking oil, shortening and margarine[90] and is used in prepared foods. There is a vanishingly small amount of protein or DNA from the original crop in vegetable oil.[72][91] Vegetable oil is made of triglycerides extracted from plants or seeds and then refined and may be further processed via hydrogenation to turn liquid oils into solids. The refining process[92] removes all, or nearly all non-triglyceride ingredients.[93] Medium-chain triglycerides (MCTs) offer an alternative to conventional fats and oils. The length of a fatty acid influences its fat absorption during the digestive process. Fatty acids in the middle position on the glycerol molecules appear to be absorbed more easily and influence metabolism more than fatty acids on the end positions. Unlike ordinary fats, MCTs are metabolized like carbohydrates. They have exceptional oxidative stability, and prevent foods from turning rancid readily.[94]

Livestock and poultry are raised on animal feed, much of which is composed of the leftovers from processing crops, including GM crops. For example, approximately 43% of a canola seed is oil. What remains after oil extraction is a meal that becomes an ingredient in animal feed and contains canola protein.[95] Likewise, the bulk of the soybean crop is grown for oil and meal. The high-protein defatted and toasted soy meal becomes livestock feed and dog food. 98% of the US soybean crop goes for livestock feed.[96][97] In 2011, 49% of the US maize harvest was used for livestock feed (including the percentage of waste from distillers grains).[98] "Despite methods that are becoming more and more sensitive, tests have not yet been able to establish a difference in the meat, milk, or eggs of animals depending on the type of feed they are fed. It is impossible to tell if an animal was fed GM soy just by looking at the resulting meat, dairy, or egg products. The only way to verify the presence of GMOs in animal feed is to analyze the origin of the feed itself."[99]

A 2012 literature review of studies evaluating the effect of GM feed on the health of animals did not find evidence that animals were adversely affected, although small biological differences were occasionally found. The studies included in the review ranged from 90 days to two years, with several of the longer studies considering reproductive and intergenerational effects.[100]

Rennet is a mixture of enzymes used to coagulate milk into cheese. Originally it was available only from the fourth stomach of calves, and was scarce and expensive, or was available from microbial sources, which often produced unpleasant tastes. Genetic engineering made it possible to extract rennet-producing genes from animal stomachs and insert them into bacteria, fungi or yeasts to make them produce chymosin, the key enzyme.[101][102] The modified microorganism is killed after fermentation. Chymosin is isolated from the fermentation broth, so that the Fermentation-Produced Chymosin (FPC) used by cheese producers has an amino acid sequence that is identical to bovine rennet.[103] The majority of the applied chymosin is retained in the whey. Trace quantities of chymosin may remain in cheese.[103]

FPC was the first artificially produced enzyme to be approved by the US Food and Drug Administration.[34][35] FPC products have been on the market since 1990 and as of 2015 had yet to be surpassed in commercial markets.[104] In 1999, about 60% of US hard cheese was made with FPC.[105] Its global market share approached 80%.[106] By 2008, approximately 80% to 90% of commercially made cheeses in the US and Britain were made using FPC.[103]

In some countries, recombinant (GM) bovine somatotropin (also called rBST, or bovine growth hormone or BGH) is approved for administration to increase milk production. rBST may be present in milk from rBST treated cows, but it is destroyed in the digestive system and even if directly injected into the human bloodstream, has no observable effect on humans.[107][108][109] The FDA, World Health Organization, American Medical Association, American Dietetic Association and the National Institutes of Health have independently stated that dairy products and meat from rBST-treated cows are safe for human consumption.[110] However, on 30 September 2010, the United States Court of Appeals, Sixth Circuit, analyzing submitted evidence, found a "compositional difference" between milk from rBGH-treated cows and milk from untreated cows.[111][112] The court stated that milk from rBGH-treated cows has: increased levels of the hormone Insulin-like growth factor 1 (IGF-1); higher fat content and lower protein content when produced at certain points in the cow's lactation cycle; and more somatic cell counts, which may "make the milk turn sour more quickly."[112]

Genetically modified livestock are organisms from the group of cattle, sheep, pigs, goats, birds, horses and fish kept for human consumption, whose genetic material (DNA) has been altered using genetic engineering techniques. In some cases, the aim is to introduce a new trait to the animals which does not occur naturally in the species, i.e. transgenesis.

A 2003 review published on behalf of Food Standards Australia New Zealand examined transgenic experimentation on terrestrial livestock species as well as aquatic species such as fish and shellfish. The review examined the molecular techniques used for experimentation as well as techniques for tracing the transgenes in animals and products as well as issues regarding transgene stability.[113]

Some mammals typically used for food production have been modified to produce non-food products, a practice sometimes called Pharming.

A GM salmon, awaiting regulatory approval[114][115][116] since 1997,[117] was approved for human consumption by the American FDA in November 2015, to be raised in specific land-based hatcheries in Canada and Panama.[118]

The use of genetically modified food-grade organisms as recombinant vaccine expression hosts and delivery vehicles can open new avenues for vaccinology. Considering that oral immunization is a beneficial approach in terms of costs, patient comfort, and protection of mucosal tissues, the use of food-grade organisms can lead to highly advantageous vaccines in terms of costs, easy administration, and safety. The organisms currently used for this purpose are bacteria (Lactobacillus and Bacillus), yeasts, algae, plants, and insect species. Several such organisms are under clinical evaluation, and the current adoption of this technology by the industry indicates a potential to benefit global healthcare systems.[119]

There is a scientific consensus[120][121][122][123] that currently available food derived from GM crops poses no greater risk to human health than conventional food,[124][125][126][127][128] but that each GM food needs to be tested on a case-by-case basis before introduction.[129][130][131] Nonetheless, members of the public are much less likely than scientists to perceive GM foods as safe.[132][133][134][135]

Opponents claim that long-term health risks have not been adequately assessed and propose various combinations of additional testing, labeling[136] or removal from the market.[137][138][139][140] The advocacy group European Network of Scientists for Social and Environmental Responsibility (ENSSER), disputes the claim that "science" supports the safety of current GM foods, proposing that each GM food must be judged on case-by-case basis.[141] The Canadian Association of Physicians for the Environment called for removing GM foods from the market pending long term health studies.[137] Multiple disputed studies have claimed health effects relating to GM foods or to the pesticides used with them.[142]

The legal and regulatory status of GM foods varies by country, with some nations banning or restricting them, and others permitting them with widely differing degrees of regulation.[143][144][145][146] Countries such as the United States, Canada, Lebanon and Egypt use substantial equivalence to determine if further testing is required, while many countries such as those in the European Union, Brazil and China only authorize GMO cultivation on a case-by-case basis. In the U.S. the FDA determined that GMO's are "Generally Recognized as Safe" (GRAS) and therefore do not require additional testing if the GMO product is substantially equivalent to the non-modified product.[147] If new substances are found, further testing may be required to satisfy concerns over potential toxicity, allergenicity, possible gene transfer to humans or genetic outcrossing to other organisms.[26]

Government regulation of GMO development and release varies widely between countries. Marked differences separate GMO regulation in the U.S. and GMO regulation in the European Union.[148] Regulation also varies depending on the intended product's use. For example, a crop not intended for food use is generally not reviewed by authorities responsible for food safety.[149]

In the U.S., three government organizations regulate GMOs. The FDA checks the chemical composition of organisms for potential allergens. The United States Department of Agriculture (USDA) supervises field testing and monitors the distribution of GM seeds. The United States Environmental Protection Agency (EPA) is responsible for monitoring pesticide usage, including plants modified to contain proteins toxic to insects. Like USDA, EPA also oversees field testing and the distribution of crops that have had contact with pesticides to ensure environmental safety.[150][bettersourceneeded] In 2015 the Obama administration announced that it would update the way the government regulated GM crops.[151]

In 1992 FDA published "Statement of Policy: Foods derived from New Plant Varieties." This statement is a clarification of FDA's interpretation of the Food, Drug, and Cosmetic Act with respect to foods produced from new plant varieties developed using recombinant deoxyribonucleic acid (rDNA) technology. FDA encouraged developers to consult with the FDA regarding any bioengineered foods in development. The FDA says developers routinely do reach out for consultations. In 1996 FDA updated consultation procedures.[152][153]

As of 2015, 64 countries require labeling of GMO products in the marketplace.[154]

US and Canadian national policy is to require a label only given significant composition differences or documented health impacts, although some individual US states (Vermont, Connecticut and Maine) enacted laws requiring them.[155][156][157][158] In July 2016, Public Law 114-214 was enacted to regulate labeling of GMO food on a national basis.

In some jurisdictions, the labeling requirement depends on the relative quantity of GMO in the product. A study that investigated voluntary labeling in South Africa found that 31% of products labeled as GMO-free had a GM content above 1.0%.[159]

In Europe all food (including processed food) or feed that contains greater than 0.9% GMOs must be labelled.[160]

Testing on GMOs in food and feed is routinely done using molecular techniques such as PCR and bioinformatics.[161]

In a January 2010 paper, the extraction and detection of DNA along a complete industrial soybean oil processing chain was described to monitor the presence of Roundup Ready (RR) soybean: "The amplification of soybean lectin gene by end-point polymerase chain reaction (PCR) was successfully achieved in all the steps of extraction and refining processes, until the fully refined soybean oil. The amplification of RR soybean by PCR assays using event-specific primers was also achieved for all the extraction and refining steps, except for the intermediate steps of refining (neutralisation, washing and bleaching) possibly due to sample instability. The real-time PCR assays using specific probes confirmed all the results and proved that it is possible to detect and quantify genetically modified organisms in the fully refined soybean oil. To our knowledge, this has never been reported before and represents an important accomplishment regarding the traceability of genetically modified organisms in refined oils."[162]

According to Thomas Redick, detection and prevention of cross-pollination is possible through the suggestions offered by the Farm Service Agency (FSA) and Natural Resources Conservation Service (NRCS). Suggestions include educating farmers on the importance of coexistence, providing farmers with tools and incentives to promote coexistence, conduct research to understand and monitor gene flow, provide assurance of quality and diversity in crops, provide compensation for actual economic losses for farmers.[163]

The genetically modified foods controversy consists of a set of disputes over the use of food made from genetically modified crops. The disputes involve consumers, farmers, biotechnology companies, governmental regulators, non-governmental organizations, environmental and political activists and scientists. The major disagreements include whether GM foods can be safely consumed, harm the environment and/or are adequately tested and regulated.[138][164] The objectivity of scientific research and publications has been challenged.[137] Farming-related disputes include the use and impact of pesticides, seed production and use, side effects on non-GMO crops/farms,[165] and potential control of the GM food supply by seed companies.[137]

The conflicts have continued since GM foods were invented. They have occupied the media, the courts, local, regional and national governments and international organizations.

The literature about Biodiversity and the GE food/feed consumption has sometimes resulted in animated debate regarding the suitability of the experimental designs, the choice of the statistical methods or the public accessibility of data. Such debate, even if positive and part of the natural process of review by the scientific community, has frequently been distorted by the media and often used politically and inappropriately in anti-GE crops campaigns.

Domingo, Jos L.; Bordonaba, Jordi Gin (2011). "A literature review on the safety assessment of genetically modified plants" (PDF). Environment International. 37: 734742. doi:10.1016/j.envint.2011.01.003. PMID21296423. In spite of this, the number of studies specifically focused on safety assessment of GM plants is still limited. However, it is important to remark that for the first time, a certain equilibrium in the number of research groups suggesting, on the basis of their studies, that a number of varieties of GM products (mainly maize and soybeans) are as safe and nutritious as the respective conventional non-GM plant, and those raising still serious concerns, was observed. Moreover, it is worth mentioning that most of the studies demonstrating that GM foods are as nutritional and safe as those obtained by conventional breeding, have been performed by biotechnology companies or associates, which are also responsible of commercializing these GM plants. Anyhow, this represents a notable advance in comparison with the lack of studies published in recent years in scientific journals by those companies.

Krimsky, Sheldon (2015). "An Illusory Consensus behind GMO Health Assessment" (PDF). Science, Technology, & Human Values. 40: 132. doi:10.1177/0162243915598381. I began this article with the testimonials from respected scientists that there is literally no scientific controversy over the health effects of GMOs. My investigation into the scientific literature tells another story.

And contrast:

Panchin, Alexander Y.; Tuzhikov, Alexander I. (January 14, 2016). "Published GMO studies find no evidence of harm when corrected for multiple comparisons". Critical Reviews in Biotechnology: 15. doi:10.3109/07388551.2015.1130684. ISSN0738-8551. PMID26767435. Here, we show that a number of articles some of which have strongly and negatively influenced the public opinion on GM crops and even provoked political actions, such as GMO embargo, share common flaws in the statistical evaluation of the data. Having accounted for these flaws, we conclude that the data presented in these articles does not provide any substantial evidence of GMO harm.

The presented articles suggesting possible harm of GMOs received high public attention. However, despite their claims, they actually weaken the evidence for the harm and lack of substantial equivalency of studied GMOs. We emphasize that with over 1783 published articles on GMOs over the last 10 years it is expected that some of them should have reported undesired differences between GMOs and conventional crops even if no such differences exist in reality.

and

Yang, Y.T.; Chen, B. (2016). "Governing GMOs in the USA: science, law and public health". Journal of the Science of Food and Agriculture. 96: 18511855. doi:10.1002/jsfa.7523. PMID26536836. It is therefore not surprising that efforts to require labeling and to ban GMOs have been a growing political issue in the USA (citing Domingo and Bordonaba, 2011).

Overall, a broad scientific consensus holds that currently marketed GM food poses no greater risk than conventional food... Major national and international science and medical associations have stated that no adverse human health effects related to GMO food have been reported or substantiated in peer-reviewed literature to date.

Despite various concerns, today, the American Association for the Advancement of Science, the World Health Organization, and many independent international science organizations agree that GMOs are just as safe as other foods. Compared with conventional breeding techniques, genetic engineering is far more precise and, in most cases, less likely to create an unexpected outcome.

Pinholster, Ginger (October 25, 2012). "AAAS Board of Directors: Legally Mandating GM Food Labels Could "Mislead and Falsely Alarm Consumers"". American Association for the Advancement of Science. Retrieved February 8, 2016.

"REPORT 2 OF THE COUNCIL ON SCIENCE AND PUBLIC HEALTH (A-12): Labeling of Bioengineered Foods" (PDF). American Medical Association. 2012. Retrieved March 19, 2016. Bioengineered foods have been consumed for close to 20 years, and during that time, no overt consequences on human health have been reported and/or substantiated in the peer-reviewed literature.

GM foods currently available on the international market have passed safety assessments and are not likely to present risks for human health. In addition, no effects on human health have been shown as a result of the consumption of such foods by the general population in the countries where they have been approved. Continuous application of safety assessments based on the Codex Alimentarius principles and, where appropriate, adequate post market monitoring, should form the basis for ensuring the safety of GM foods.

"Genetically modified foods and health: a second interim statement" (PDF). British Medical Association. March 2004. Retrieved March 21, 2016. In our view, the potential for GM foods to cause harmful health effects is very small and many of the concerns expressed apply with equal vigour to conventionally derived foods. However, safety concerns cannot, as yet, be dismissed completely on the basis of information currently available.

When seeking to optimise the balance between benefits and risks, it is prudent to err on the side of caution and, above all, learn from accumulating knowledge and experience. Any new technology such as genetic modification must be examined for possible benefits and risks to human health and the environment. As with all novel foods, safety assessments in relation to GM foods must be made on a case-by-case basis.

Members of the GM jury project were briefed on various aspects of genetic modification by a diverse group of acknowledged experts in the relevant subjects. The GM jury reached the conclusion that the sale of GM foods currently available should be halted and the moratorium on commercial growth of GM crops should be continued. These conclusions were based on the precautionary principle and lack of evidence of any benefit. The Jury expressed concern over the impact of GM crops on farming, the environment, food safety and other potential health effects.

The Royal Society review (2002) concluded that the risks to human health associated with the use of specific viral DNA sequences in GM plants are negligible, and while calling for caution in the introduction of potential allergens into food crops, stressed the absence of evidence that commercially available GM foods cause clinical allergic manifestations. The BMA shares the view that that there is no robust evidence to prove that GM foods are unsafe but we endorse the call for further research and surveillance to provide convincing evidence of safety and benefit.

The literature about Biodiversity and the GE food/feed consumption has sometimes resulted in animated debate regarding the suitability of the experimental designs, the choice of the statistical methods or the public accessibility of data. Such debate, even if positive and part of the natural process of review by the scientific community, has frequently been distorted by the media and often used politically and inappropriately in anti-GE crops campaigns.

Domingo, Jos L.; Bordonaba, Jordi Gin (2011). "A literature review on the safety assessment of genetically modified plants" (PDF). Environment International. 37: 734742. doi:10.1016/j.envint.2011.01.003. PMID21296423. In spite of this, the number of studies specifically focused on safety assessment of GM plants is still limited. However, it is important to remark that for the first time, a certain equilibrium in the number of research groups suggesting, on the basis of their studies, that a number of varieties of GM products (mainly maize and soybeans) are as safe and nutritious as the respective conventional non-GM plant, and those raising still serious concerns, was observed. Moreover, it is worth mentioning that most of the studies demonstrating that GM foods are as nutritional and safe as those obtained by conventional breeding, have been performed by biotechnology companies or associates, which are also responsible of commercializing these GM plants. Anyhow, this represents a notable advance in comparison with the lack of studies published in recent years in scientific journals by those companies.

Krimsky, Sheldon (2015). "An Illusory Consensus behind GMO Health Assessment" (PDF). Science, Technology, & Human Values. 40: 132. doi:10.1177/0162243915598381. I began this article with the testimonials from respected scientists that there is literally no scientific controversy over the health effects of GMOs. My investigation into the scientific literature tells another story.

And contrast:

Panchin, Alexander Y.; Tuzhikov, Alexander I. (January 14, 2016). "Published GMO studies find no evidence of harm when corrected for multiple comparisons". Critical Reviews in Biotechnology: 15. doi:10.3109/07388551.2015.1130684. ISSN0738-8551. PMID26767435. Here, we show that a number of articles some of which have strongly and negatively influenced the public opinion on GM crops and even provoked political actions, such as GMO embargo, share common flaws in the statistical evaluation of the data. Having accounted for these flaws, we conclude that the data presented in these articles does not provide any substantial evidence of GMO harm.

The presented articles suggesting possible harm of GMOs received high public attention. However, despite their claims, they actually weaken the evidence for the harm and lack of substantial equivalency of studied GMOs. We emphasize that with over 1783 published articles on GMOs over the last 10 years it is expected that some of them should have reported undesired differences between GMOs and conventional crops even if no such differences exist in reality.

and

Yang, Y.T.; Chen, B. (2016). "Governing GMOs in the USA: science, law and public health". Journal of the Science of Food and Agriculture. 96: 18511855. doi:10.1002/jsfa.7523. PMID26536836. It is therefore not surprising that efforts to require labeling and to ban GMOs have been a growing political issue in the USA (citing Domingo and Bordonaba, 2011).

Overall, a broad scientific consensus holds that currently marketed GM food poses no greater risk than conventional food... Major national and international science and medical associations have stated that no adverse human health effects related to GMO food have been reported or substantiated in peer-reviewed literature to date.

Despite various concerns, today, the American Association for the Advancement of Science, the World Health Organization, and many independent international science organizations agree that GMOs are just as safe as other foods. Compared with conventional breeding techniques, genetic engineering is far more precise and, in most cases, less likely to create an unexpected outcome.

Pinholster, Ginger (October 25, 2012). "AAAS Board of Directors: Legally Mandating GM Food Labels Could "Mislead and Falsely Alarm Consumers"". American Association for the Advancement of Science. Retrieved February 8, 2016.

"REPORT 2 OF THE COUNCIL ON SCIENCE AND PUBLIC HEALTH (A-12): Labeling of Bioengineered Foods" (PDF). American Medical Association. 2012. Retrieved March 19, 2016. Bioengineered foods have been consumed for close to 20 years, and during that time, no overt consequences on human health have been reported and/or substantiated in the peer-reviewed literature.

GM foods currently available on the international market have passed safety assessments and are not likely to present risks for human health. In addition, no effects on human health have been shown as a result of the consumption of such foods by the general population in the countries where they have been approved. Continuous application of safety assessments based on the Codex Alimentarius principles and, where appropriate, adequate post market monitoring, should form the basis for ensuring the safety of GM foods.

"Genetically modified foods and health: a second interim statement" (PDF). British Medical Association. March 2004. Retrieved March 21, 2016. In our view, the potential for GM foods to cause harmful health effects is very small and many of the concerns expressed apply with equal vigour to conventionally derived foods. However, safety concerns cannot, as yet, be dismissed completely on the basis of information currently available.

When seeking to optimise the balance between benefits and risks, it is prudent to err on the side of caution and, above all, learn from accumulating knowledge and experience. Any new technology such as genetic modification must be examined for possible benefits and risks to human health and the environment. As with all novel foods, safety assessments in relation to GM foods must be made on a case-by-case basis.

Members of the GM jury project were briefed on various aspects of genetic modification by a diverse group of acknowledged experts in the relevant subjects. The GM jury reached the conclusion that the sale of GM foods currently available should be halted and the moratorium on commercial growth of GM crops should be continued. These conclusions were based on the precautionary principle and lack of evidence of any benefit. The Jury expressed concern over the impact of GM crops on farming, the environment, food safety and other potential health effects.

The Royal Society review (2002) concluded that the risks to human health associated with the use of specific viral DNA sequences in GM plants are negligible, and while calling for caution in the introduction of potential allergens into food crops, stressed the absence of evidence that commercially available GM foods cause clinical allergic manifestations. The BMA shares the view that that there is no robust evidence to prove that GM foods are unsafe but we endorse the call for further research and surveillance to provide convincing evidence of safety and benefit.

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Genetically modified food - Wikipedia

PHG Foundation – Interactive Tutorial: Pharmacogenomics …

Pharmacogenetics refers to the study of genetic influences on an individuals response to drugs. In pharmacogenetics, the analysis of a specific gene, or group of genes, may be used to predict responses to a specific drug or class of drugs.

Pharmacogenomics refers collectively to all the genes that influence drug responses, and how genome-wide analysis may be used to identify such genes in the search for novel drug targets and/or key determinants of drug reactions.

The effects of a specific dose of a specific drug will differ between individual recipients. A drug that is effective in one person may have no discernible therapeutic effect in another, whilst a third might show a partial response; in some, there may be undesirable side-effects.

There are multiple contributory factors to such variation in drug response, such as gender, age, body mass, diet, the presence of other drugs or of particular disease states and exposure to certain chemicals or toxins, such as cigarette smoke. In addition to these, genetic factors also influence drug response.

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Anatomy and Physiology – McGraw Hill Education

Glossary Click here to go to Prefixes and Suffixes.

Most of the words in this glossary are followed by a phonetic spelling that serves as a guide to pronunciation. The phonetic spellings reflect standard scientific usage and can be easily interpreted following a few basic rules.

abduction (ab-dukshun) The movement of a body part away from the axis or midline of the body; movement of a digit away from the axis of the limb.

ABO system The most common system of classification for red blood cell antigens. On the basis of antigens on the red blood cell surface, individuals can be type A, type B, type AB, or type O.

absorption (ab-sorpshun) The transport of molecules across epithelial membranes into the body fluids.

accessory organs (ak-sesuo-re) Organs that assist with the functioning of other organs within a system.

accommodation (ua-komuo-dashun) A process whereby the focal length of the eye is changed by automatic adjustment of the curvature of the lens to bring images of objects from various distances into focus on the retina.

acetabulum (asue-tabyuu-lum) A socket in the lateral surface of the hipbone (os coxa) with which the head of the femur articulates.

acetone (asue-t=on) A ketone body produced as a result of the oxidation of fats.

acetyl coenzyme A (acetyl CoA) (asue-tl, ua-setl) A coenzyme derivative in the metabolism of glucose and fatty acids that contributes substrates to the Krebs cycle.

acetylcholine (ACh) (ua-setl-kol=en) An acetic acid ester of choline-a substance that functions as a neurotransmitter in somatic motor nerve and parasympathetic nerve fibers.

acetylcholinesterase (ua-setl-kolu1-nestue-r=as) An enzyme in the membrane of postsynaptic cells that catalyzes the conversion of ACh into choline and acetic acid. This enzymatic reaction inactivates the neurotransmitter.

Achilles tendon (ua-kil=ez) See tendo calcaneous.

acid (asid) A substance that releases hydrogen ions when ionized in water.

acidosis (asu1-dosis) An abnormal increase in the H+ concentration of the blood that lowers the arterial pH to below 7.35.

acromegaly (akro-megua-le) A condition caused by the hypersecretion of growth hormone from the pituitary gland after maturity and characterized by enlargement of the extremities, such as the nose, jaws, fingers, and toes.

actin (aktin) A protein in muscle fibers that together with myosin is responsible for contraction.

action potential An all-or-none electrical event in an axon or muscle fiber in which the polarity of the membrane potential is rapidly reversed and reestablished.

active immunity (u1-myoonu1-te) Immunity involving sensitization, in which antibody production is stimulated by prior exposure to an antigen.

active transport The movement of molecules or ions across the cell membranes of epithelial cells by membrane carriers. An expenditure of cellular energy (ATP) is required.

adduction (au-dukshun) The movement of a body part toward the axis or midline of the body; movement of a digit toward the axis of the limb.

adenohypophysis (adn-o-hi-pofu1-sis) The anterior, glandular lobe of the pituitary gland that secretes FSH (follicle-stimulating hormone), LH (luteinizing hormone), ACTH (adrenocorticotropic hormone), TSH (thyroid-stimulating hormone), GH (growth hormone), and prolactin. Secretions of the adenohypophysis are controlled by hormones produced by the hypothalamus.

adenoids (adue-noidz) The tonsils located in the nasopharynx; pharyngeal tonsils.

adenylate cyclase (ua-denl-it sikl=as) An enzyme found in cell membranes that catalyzes the conversion of ATP to cyclic AMP and pyrophosphate (PP1). This enzyme is activated by an interaction between a specific hormone and its membrane receptor protein.

ADH Antidiuretic hormone; a hormone produced by the hypothalamus and released by the posterior pituitary that acts on the kidneys to promote water reabsorption; also known as vasopressin.

ADP Adenosine diphosphate; a molecule that together with inorganic phosphate is used to make ATP (adenosine triphosphate).

adrenal cortex (ua-drenal korteks) The outer part of the adrenal gland. Derived from embryonic mesoderm, the adrenal cortex secretes corticosteroid hormones (such as aldosterone and hydrocortisone).

adrenal medulla (mue-dulua) The inner part of the adrenal gland. Derived from embryonic postganglionic sympathetic neurons, the adrenal medulla secretes catecholamine hormones-epinephrine and (to a lesser degree) norepinephrine.

adrenergic (adreu-nerjik) A term used to describe the actions of epinephrine, norepinephrine, or other molecules with similar activity (as in adrenergic receptor and adrenergic stimulation).

adventitia (adven-tishua) The outermost epithelial layer of a visceral organ; also called serosa.

afferent (afer-ent) Conveying or transmitting to.

afferent arteriole (ar-tire-=ol) A blood vessel within the kidney that supplies blood to the glomerulus.

afferent neuron (nooron) See sensory neuron.

agglutinate (ua-glootn-=at) A clump of cells (usually erythrocytes) formed as a result of specific chemical interaction between surface antigens and antibodies.

agranular leukocytes (ua-granyuu-lar loo kuo-s1=tz) White blood cells (leukocytes) that do not contain cytoplasmic granules; specifically, lymphocytes and monocytes.

albumin (al-byoomin) A water-soluble protein produced in the liver; the major component of the plasma proteins.

aldosterone (al-doster-=on) The principal corticosteroid hormone involved in the regulation of electrolyte balance (mineralocorticoid).

alimentary canal The tubular portion of the digestive tract. See also gastrointestinal tract (GI tract).

allantois (ua-lanto-is) An extraembryonic membranous sac involved in the formation of blood cells. It gives rise to the fetal umbilical arteries and vein and also contributes to the formation of the urinary bladder.

allergens (aler-jenz) Antigens that evoke an allergic response rather than a normal immune response.

allergy (aler-je) A state of hypersensitivity caused by exposure to allergens. It results in the liberation of histamine and other molecules with histaminelike effects.

all-or-none principle The statement of the fact that muscle fibers of a motor unit contract to their maximum extent when exposed to a stimulus of threshold strength.

allosteric (aluo-sterik) A term used with reference to the alteration of an enzyme's activity as a result of its combination with a regulator molecule. Allosteric inhibition by an end product represents negative feedback control of an enzyme's activity.

alveolar sacs (al-veuo-lar) A cluster of alveoli that share a common chamber or central atrium.

alveolus (al-veuo-lus) 1.An individual air capsule within the lung. The alveoli are the basic functional units of respiration. 2.The socket that secures a tooth(tooth socket).

amniocentesis (amne-o-sen-tesis) A procedure in which a sample of amniotic fluid is aspirated to examine suspended cells for various genetic diseases.

amnion (amne-on) A developmental membrane surrounding the fetus that contains amniotic fluid.

amphiarthrosis (amfe-ar-throsis) A slightly movable articulation in a functional classification of joints.

amphoteric (am-fo-terik) Having both acidic and basic characteristics; used to denote a molecule that can be positively or negatively charged, depending on the pH of its environment.

ampulla (am-poolua) A saclike enlargement of a duct or tube.

ampulla of Vater (Fuater) See hepatopancreatic ampulla.

anabolic steroids (anua-bolik steroidz) Steroids with androgenlike stimulatory effects on protein synthesis.

anabolism (ua-nabuo-lizem) A phase of metabolism involving chemical reactions within cells that result in the production of larger molecules from smaller ones; specifically, the synthesis of protein, glycogen, and fat.

anaerobic respiration (an-ua-robik respu1-rashun) A form of cell respiration involving the conversion of glucose to lactic acid in which energy is obtained without the use of molecular oxygen.

anal canal (anal) The terminal tubular portion of the large intestine that opens through the anus of the GI tract.

anaphylaxis (anua-fu1-laksis) An unusually severe allergic reaction that can result in cardiovascular shock and death.

anastomosis (ua-nastuo-mosis) An interconnecting aggregation of blood vessels or nerves that form a network plexus.

anatomical position (anua-tomu1-kal) An erect body stance with the eyes directed interior, the arms at the sides, the palms of the hands facing interior, and the fingers pointing straight down.

anatomy (ua-natuo-me) The branch of science concerned with the structure of the body and the relationship of its organs.

androgens (andruo-jenz) Steroids containing 18 carbons that have masculinizing effects; primarily those hormones(such as testosterone) secreted by the testes, although weaker androgens are also secreted by the adrenal cortex.

anemia (ua-neme-ua) An abnormal reduction in the red blood cell count, hemoglobin concentration, or hematocrit, or any combination of these measurements. This condition is associated with a decreased ability of the blood to carry oxygen.

angina pectoris (an-jinua pektuo-ris) A thoracic pain, often referred to the left pectoral and arm area, caused by myocardial ischemia.

angiotensin II (anje-o-tensin) An 8-amino-acid polypeptide formed from angiotensin I(a 10-amino-acid precursor), which in turn is formed from cleavage of a protein(angiotensinogen) by the action of renin(an enzyme secreted by the kidneys). Angiotensin II is a powerful vasoconstrictor and a stimulator of aldosterone secretion from the adrenal cortex.

anions (ani-onz) Ions that are negatively charged, such as chloride, bicarbonate, and phosphate.

antagonist (an-taguo-nist) A muscle that acts in opposition to another muscle.

antebrachium (ante-brake-em) The forearm.

anterior (ventral) Toward the front; the opposite of posterior, or dorsal.

anterior pituitary (pu1-toou1-ter-e) See adenohypophysis.

anterior root The anterior projection of the spinal cord, composed of axons of motor neurons.

antibodies (antu1-bod=ez) Immunoglobin proteins secreted by B lymphocytes that have transformed into plasma cells. Antibodies are responsible for humoral immunity. Their synthesis is induced by specific antigens, and they combine with these specific antigens but not with unrelated antigens.

anticodon (antu1-kodon) A base triplet provided by three nucleotides within a loop of transfer RNA that is complementary in its base-pairing properties to a triplet(the codon) in mRNA. The matching of codon to anticodon provides the mechanism for translating the genetic code into a specific sequence of amino acids.

antigen (antu1-jen) A molecule that can induce the production of antibodies and react in a specific manner with antibodies.

antigenic determinant site (an-tu1-jenik) The region of an antigen molecule that specifically reacts with particular antibodies. A large antigen molecule may have a number of such sites.

antiserum (antu1-sirum) A serum that contains specific antibodies.

anus (anus) The terminal opening of the GI tract.

aorta (a-ortua) The major systemic vessel of the arterial system of the body, emerging from the left ventricle.

aortic arch The superior left bend of the aorta between the ascending and descending portions.

apex (apeks) The tip or pointed end of a conical structure.

aphasia (ua-fazhua) Defects in speech, writing, or in the comprehension of spoken or written language caused by brain damage or disease.

apneustic center (ap-noostik) A collection of nuclei(nerve cell bodies) in the brain stem that participates in the rhythmic control of breathing.

apocrine gland (apuo-krin) A type of sweat gland that functions in evaporative cooling. It may respond during periods of emotional stress.

aponeurosis (apuo-noo-rosis) A fibrous or membranous sheetlike tendon.

appendix A short pouch that attaches to the cecum.

aqueous humor (akwe-us) The watery fluid that fills the anterior and posterior chambers of the eye.

arachnoid mater (ua-raknoid) The weblike middle covering(meninx) of the central nervous system.

arbor vitae (arbor vite) The branching arrangement of white matter within the cerebellum.

arm (brachium) The portion of the upper extremity from the shoulder to the elbow.

arrector pili muscle (ah-rektor pihle) The smooth muscle attached to a hair follicle that, upon contraction, pulls the hair into a more vertical position, resulting in "goose bumps."

arteriole (ar-tire-=ol) A minute arterial branch.

arteriosclerosis (ar-tire-o-sklue-rosis) Any one of a group of diseases characterized by thickening and hardening of the artery wall and in the narrowing of its lumen.

arteriovenous anastomoses (ar-tire-o-venus ua-nastuo-mos=ez) Direct connections between arteries and veins that bypass capillary beds.

artery (artue-re) A blood vessel that carries blood away from the heart.

arthrology (ar-throluo-je) The scientific study of the structure and function of joints.

articular cartilage (ar-tikyuu-lar kartu1-lij) A hyaline cartilaginous covering over the articulating surface of the bones of synovial joints.

articulation (ar-tikyuu-lashun) A joint.

arytenoid cartilages (arue-tenoid) A pair of small cartilages located on the superior aspect of the larynx.

ascending colon (kolon) The portion of the large intestine between the cecum and the hepatic flexure.

association neuron (nooron) A nerve cell located completely within the central nervous system. It conveys impulses in an arc from sensory to motor neurons; also called interneuron or internuncial neuron.

astigmatism (ua-stigmua-tizem) Unequal curvature of the refractive surfaces of the eye (cornea and/or lens), so that light entering the eye along certain meridians does not focus on the retina.

atherosclerosis (athue-ro-sklue-rosis) A common type of arteriosclerosis found in medium and larger arteries in which raised areas within the tunica intima are formed from smooth muscle cells, cholesterol, and other lipids. These plaques occlude arteries and serve as sites for the formation of thrombi.

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Anatomy and Physiology - McGraw Hill Education

GHEA – Local Classes

Participating in an Accredited Program

What are the advantages:

It will simplify the admissions process to a Georgia State School

It will simplify your record keeping

What are the disadvantages:

You will lose control of the curriculum your students use

You will lose control of your school schedule

You will lose control of directing your child's education

The pioneers of the modern home school movement have fought and won many hard battles to win the freedoms we have today to control the education of our children. Why do we so easily give it up for a convenience? For every family that signs on to an accredited program, homeschooling moves one step closer to making accredited programs a requirement for us all.

The followingweb sitesdo not include accredited programs. If you feel youneed an accredited program go to the Georgia Accrediting Commission web page.

The Georgia Home Education Association's mission is to support and encourage home based, parent directed, privately funded, Christ centered education, therefore, we do not encourage enrollment in accrediated home education programs or government/public school at home.

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GHEA - Local Classes

NY Stem Cell Treatment | Stem Cell Therapy Clinics …

Welcome to the New York Stem Cell Treatment Center. I am David Borenstein, MD, founder of the center, which is part of my practice, Manhattan Integrative Medicine.

Whether we are treating patients from New York City, Montreal or Toronto, we are dedicated to the advancement of quality care in the area of adult stem cell regenerative medicine. Our mission is to use advanced stem cell technology in order to improve the bodys ability to regenerate, heal and overcome a variety of inflammatory and degenerative conditions.

Therapies are provided at our stem cell clinic for patientsfrom all over the U.S. and around the world. Locations we serve includethe surrounding areas of Manhattan, Brooklyn, Queens, the Bronx, Staten Island, Nassau County, Suffolk County, Long Island, Westchester, New Jersey, Connecticut and Pennsylvania. We treat patientswho visit us from Canada as well, from cities such as Montreal and Toronto.

Feel free to learn more about our stem cell treatments and our stem cell clinic. If you have further questions please go ahead andcontact us, and if you would like to schedule an initial consultation, please fill out acandidate application.

Financing and banking options for stem cell therapy procedures with the New York Stem Cell Treatment Center are available through United Medical Credit. Thousands of patients have trusted United Medical Credit to secure affordable payment plans for their procedures. United Medical Credit can do the same for you!

Below are some of the benefits of choosing United Medical Credit to finance your stem cell therapy:

Dr. David Borenstein obtained his medical degree from the Technion Faculty of Medicine in Haifa, Israel and completed his internship at Staten Island University Hospital. He has completed residencies at: University Hospital at Stony Brook; Westchester County Medical Center; and St. Charles Hospital and Rehabilitation Center.

During the course of his career he has attended numerous specialized training courses in order to expand the scope of his medical expertise that he uses every day at his stem cell treatment center. He is board certified in Physical Medicine and Rehabilitation, certified in Medical Acupuncture, and is a member of numerous professional societies.

Dr. Borenstein has held many prestigious clinical appointments and positions in leading medical facilities. He has been published in the European Journal of Ultrasound and has been the Chief Investigator on a research project on Spinal Cord Injuries. He has conducted medical missions in North Korea, Ghana, Cuba, and other countries.

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NY Stem Cell Treatment | Stem Cell Therapy Clinics ...

Marine Chemist Service, Inc. | Protecting People and …

WelcomeMarine Chemist Service welcomes you to their newly revised website. In addition to a different look, the site has been updated with their latest products and services. There is also an abundance of useful, technical information ranging from safety to environmental topics. [Read More]

Credentials Marine Chemist Service is a highly diversified Virginia corporation that has two separate facilities, 10 different products and services, and 48 years of experience. The corporation also has one of the longest, continuously operating asbestos analytical laboratories. Throughout its history, MCS has trained approximately 15,000 student/employees, analyzed nearly 450,000 samples, and performed countless inspections aboard ship and within the facilities of land-side operations. This remarkable achievement has been made possibly through the efforts of 30+ biologists, chemists, geologists, industrial hygienists, inspectors, safety professionals, trainers, and a group of very efficient support personnel. [Read More]

History Well over four decades ago, in 1966, Bob and Sally Walker had a vision to develop a company dedicated to serving the maritime industry. Mr. Walker trained to become a National Fire Protection Association (NFPA) Certified Marine Chemist (which, in turn, lead to the company's name). Mrs. Walker worked behind the lines, eventually taking care of all the books, paperwork, phones and more. Together, they worked hard in pursuit of their goal and in November of that same year, the Walkers formed Marine Chemist Service in the historic state of Virginia. [Read More]

In the News Marine Chemist Service is passionate about Protecting People and their Environment. That passion is often demonstrated by sharing free information via consultation and the Information/Links page found on its website. Marine Chemist Service also subscribes to several news organizations, participates in numerous committees and boards, and conducts its own original research. The content of some of the aforementioned is available here, [In the News]

Training Marine Chemist Service has trained approximately 13,500 student-employees throughout its history. The company offers over 30 courses, has four full time and other guest instructors, and two locations in the Tidewater area of Virginia. The company has also provided offsite training within the CONUS, including the states of Florida, Mississippi, North Carolina and Wisconsin. They have even provided training as far away as Bahamas and Japan. When requested, Marine Chemist Service has customized its courses to focus application on unusual hazards and/or unique work practices to protect against those hazards. [Read More]

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Marine Chemist Service takes great pleasure in servicing its clients needs. In that effort, MCS offers a continuously updated newsletter, as well as additional information on the below products and services.

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Marine Chemist Service, Inc. | Protecting People and ...

History of biochemistry – Wikipedia

The history of biochemistry can be said to have started with the ancient Greeks who were interested in the composition and processes of life, although biochemistry as a specific scientific discipline has its beginning around the early 19th century.[1] Some argued that the beginning of biochemistry may have been the discovery of the first enzyme, diastase (today called amylase), in 1833 by Anselme Payen,[2] while others considered Eduard Buchner's first demonstration of a complex biochemical process alcoholic fermentation in cell-free extracts to be the birth of biochemistry.[3][4] Some might also point to the influential work of Justus von Liebig from 1842, Animal chemistry, or, Organic chemistry in its applications to physiology and pathology, which presented a chemical theory of metabolism,[1] or even earlier to the 18th century studies on fermentation and respiration by Antoine Lavoisier.[5][6]

The term biochemistry itself is derived from the combining form bio-, meaning "life", and chemistry. The word is first recorded in English in 1848,[7] while in 1877, Felix Hoppe-Seyler used the term (Biochemie in German) in the foreword to the first issue of Zeitschrift fr Physiologische Chemie (Journal of Physiological Chemistry) as a synonym for physiological chemistry and argued for the setting up of institutes dedicate to its studies.[8][9] Nevertheless, several sources cite German chemist Carl Neuberg as having coined the term for the new discipline in 1903,[10][11] and some credit it to Franz Hofmeister.[12]

The subject of study in biochemistry is the chemical processes in living organisms, and its history involves the discovery and understanding of the complex components of life and the elucidation of pathways of biochemical processes. Much of biochemistry deals with the structures and functions of cellular components such as proteins, carbohydrates, lipids, nucleic acids and other biomolecules; their metabolic pathways and flow of chemical energy through metabolism; how biological molecules give rise to the processes that occur within living cells; it also focuses on the biochemical processes involved in the control of information flow through biochemical signalling, and how they relate to the functioning of whole organisms. Over the last 40 years the field has had success in explaining living processes such that now almost all areas of the life sciences from botany to medicine are engaged in biochemical research.

Among the vast number of different biomolecules, many are complex and large molecules (called polymers), which are composed of similar repeating subunits (called monomers). Each class of polymeric biomolecule has a different set of subunit types. For example, a protein is a polymer whose subunits are selected from a set of twenty or more amino acids, carbohydrates are formed from sugars known as monosaccharides, oligosaccharides, and polysaccharides, lipids are formed from fatty acids and glycerols, and nucleic acids are formed from nucleotides. Biochemistry studies the chemical properties of important biological molecules, like proteins, and in particular the chemistry of enzyme-catalyzed reactions. The biochemistry of cell metabolism and the endocrine system has been extensively described. Other areas of biochemistry include the genetic code (DNA, RNA), protein synthesis, cell membrane transport, and signal transduction.

In these regards, the study of biochemistry began when biology first began to interest societyas the ancient Chinese developed a system of medicine based on yin and yang, and also the five phases,[13] which both resulted from alchemical and biological interests. It began in the ancient Indian culture also with an interest in medicine, as they developed the concept of three humors that were similar to the Greek's four humours (see humorism). They also delved into the interest of bodies being composed of tissues. As in the majority of early sciences, the Islamic world greatly contributed to early biological advancements as well as alchemical advancements; especially with the introduction of clinical trials and clinical pharmacology presented in Avicenna's The Canon of Medicine.[14] On the side of chemistry, early advancements were heavily attributed to exploration of alchemical interests but also included: metallurgy, the scientific method, and early theories of atomism. In more recent times, the study of chemistry was marked by milestones such as the development of Mendeleev's periodic table, Dalton's atomic model, and the conservation of mass theory. This last mention has the most importance of the three due to the fact that this law intertwines chemistry with thermodynamics in an intercalated manner.

As early as the late 18th century and early 19th century, the digestion of meat by stomach secretions[15] and the conversion of starch to sugars by plant extracts and saliva were known. However, the mechanism by which this occurred had not been identified.[16]

In the 19th century, when studying the fermentation of sugar to alcohol by yeast, Louis Pasteur concluded that this fermentation was catalyzed by a vital force contained within the yeast cells called ferments, which he thought functioned only within living organisms. He wrote that "alcoholic fermentation is an act correlated with the life and organization of the yeast cells, not with the death or putrefaction of the cells."[17]

Anselme Payen discovered in 1833 the first enzyme who called diastase[18] and in 1878 German physiologist Wilhelm Khne (18371900) coined the term enzyme, which comes from Greek "in leaven", to describe this process. The word enzyme was used later to refer to nonliving substances such as pepsin, and the word ferment used to refer to chemical activity produced by living organisms.

In 1897 Eduard Buchner began to study the ability of yeast extracts to ferment sugar despite the absence of living yeast cells. In a series of experiments at the University of Berlin, he found that the sugar was fermented even when there were no living yeast cells in the mixture.[19] He named the enzyme that brought about the fermentation of sucrose "zymase".[20] In 1907 he received the Nobel Prize in Chemistry "for his biochemical research and his discovery of cell-free fermentation". Following Buchner's example; enzymes are usually named according to the reaction they carry out. Typically the suffix -ase is added to the name of the substrate (e.g., lactase is the enzyme that cleaves lactose) or the type of reaction (e.g., DNA polymerase forms DNA polymers).

Having shown that enzymes could function outside a living cell, the next step was to determine their biochemical nature. Many early workers noted that enzymatic activity was associated with proteins, but several scientists (such as Nobel laureate Richard Willsttter) argued that proteins were merely carriers for the true enzymes and that proteins per se were incapable of catalysis. However, in 1926, James B. Sumner showed that the enzyme urease was a pure protein and crystallized it; Sumner did likewise for the enzyme catalase in 1937. The conclusion that pure proteins can be enzymes was definitively proved by Northrop and Stanley, who worked on the digestive enzymes pepsin (1930), trypsin and chymotrypsin. These three scientists were awarded the 1946 Nobel Prize in Chemistry.[21]

This discovery, that enzymes could be crystallized, meant that scientists eventually could solve their structures by x-ray crystallography. This was first done for lysozyme, an enzyme found in tears, saliva and egg whites that digests the coating of some bacteria; the structure was solved by a group led by David Chilton Phillips and published in 1965.[22] This high-resolution structure of lysozyme marked the beginning of the field of structural biology and the effort to understand how enzymes work at an atomic level of detail.

The term metabolism is derived from the Greek Metabolismos for "change", or "overthrow".[23] The history of the scientific study of metabolism spans 800 years. The earliest of all metabolic studies began during the early thirteenth century (1213-1288) by a Muslim scholar from Damascus named Ibn al-Nafis. al-Nafis stated in his most well-known work Theologus Autodidactus that "that body and all its parts are in a continuous state of dissolution and nourishment, so they are inevitably undergoing permanent change."[24] Although al-Nafis was the first documented physician to have an interest in biochemical concepts, the first controlled experiments in human metabolism were published by Santorio Santorio in 1614 in his book Ars de statica medecina.[25] This book describes how he weighed himself before and after eating, sleeping, working, sex, fasting, drinking, and excreting. He found that most of the food he took in was lost through what he called "insensible perspiration".

One of the most prolific of these modern biochemists was Hans Krebs who made huge contributions to the study of metabolism.[26] He discovered the urea cycle and later, working with Hans Kornberg, the citric acid cycle and the glyoxylate cycle.[27][28][29] These discoveries led to Krebs being awarded the Nobel Prize in physiology in 1953,[30] which was shared with the German biochemist Fritz Albert Lipmann who also codiscovered the essential cofactor coenzyme A.

In 1960, the biochemist Robert K. Crane revealed his discovery of the sodium-glucose cotransport as the mechanism for intestinal glucose absorption.[31] This was the very first proposal of a coupling between the fluxes of an ion and a substrate that has been seen as sparking a revolution in biology. This discovery, however, would not have been possible if it were not for the discovery of the molecule glucose's structure and chemical makeup. These discoveries are largely attributed to the German chemist Emil Fischer who received the Nobel Prize in chemistry nearly 60 years earlier.[32]

Since metabolism focuses on the breaking down (catabolic processes) of molecules and the building of larger molecules from these particles (anabolic processes), the use of glucose and its involvement in the formation of adenosine triphosphate (ATP) is fundamental to this understanding. The most frequent type of glycolysis found in the body is the type that follows the Embden-Meyerhof-Parnas (EMP) Pathway, which was discovered by Gustav Embden, Otto Meyerhof, and Jakob Karol Parnas. These three men discovered that glycolysis is a strongly determinant process for the efficiency and production of the human body. The significance of the pathway shown in the adjacent image is that by identifying the individual steps in this process doctors and researchers are able to pinpoint sites of metabolic malfunctions such as pyruvate kinase deficiency that can lead to severe anemia. This is most important because cells, and therefore organisms, are not capable of surviving without proper functioning metabolic pathways.

Since then, biochemistry has advanced, especially since the mid-20th century, with the development of new techniques such as chromatography, X-ray diffraction, NMR spectroscopy, radioisotopic labelling, electron microscopy and molecular dynamics simulations. These techniques allowed for the discovery and detailed analysis of many molecules and metabolic pathways of the cell, such as glycolysis and the Krebs cycle (citric acid cycle). The example of an NMR instrument shows that some of these instruments, such as the HWB-NMR, can be very large in size and can cost anywhere from a few hundred dollars to millions of dollars ($16 million for the one shown here).

Polymerase chain reaction (PCR) is the primary gene amplification technique that has revolutionized modern biochemistry. Polymerase chain reaction was developed by Kary Mullis in 1983.[33] There are four steps to a proper polymerase chain reaction: 1) denaturation 2) extension 3) insertion (of gene to be expressed) and finally 4) amplification of the inserted gene. These steps with simple illustrative examples of this process can be seen in the image below and to the right of this section. This technique allows for the copy of a single gene to be amplified into hundreds or even millions of copies and has become a cornerstone in the protocol for any biochemist that wishes to work with bacteria and gene expression. PCR is not only used for gene expression research but is also capable of aiding laboratories in diagnosing certain diseases such a lymphomas, some types of leukemia, and other malignant diseases that can sometimes puzzle doctors. Without polymerase chain reaction development, there are many advancements in the field of bacterial study and protein expression study that would not have come to fruition.[34] The development of the theory and process of polymerase chain reaction is essential but the invention of the thermal cycler is equally as important because the process would not be possible without this instrument. This is yet another testament to the fact that the advancement of technology is just as crucial to sciences such as biochemistry as is the painstaking research that leads to the development of theoretical concepts.

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History of biochemistry - Wikipedia

Department of Microbiology and Immunology | University of …

The Department of Microbiology and Immunology provides a stimulating environment for faculty scientists and trainees who will play a leadership role in academic, government and industrial research and in international health organizations.

Advances in molecular and cell biology and genetics have opened new approaches to the basic and applied aspects of infectious diseases and host defenses. We are applying these approaches to basic aspects of receptor signaling, regulation of gene expression in both prokaryotic and eukaryotic cells and interactions between these cells, genetic manipulation of cellular functions, microbial genomics and evolution, and development of new vaccination strategies. The techniques of functional genomics, gene delivery, stem cells and transgenic/gene disruption animal models are being developed to address specific questions.

TheGraduate Program in Molecular Microbiology and Immunologyprovides interactive, multi-departmental graduate education and research training. Our graduates receive comprehensive education in molecular and cell biology, microbiology and immunology and in-depth training in their chosen area of research.

Our Ph.D. and M.D./Ph.D. students train in the laboratories of participating faculty in theInstitute for Genome Sciences,Center for Vaccine Development,Institute of Human Virology,Department of Microbial Pathogenesisin the Dental School, theUniversity of Maryland Marlene & Stewart Greenebaum Cancer Center, theProgram in the Biology of Model Systems; and the Departments ofMedicine,SurgeryandPediatrics.

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Gene – Wikipedia

This article is about the heritable unit for transmission of biological traits. For other uses, see Gene (disambiguation).

A gene is a locus (or region) of DNA which is made up of nucleotides and is the molecular unit of heredity.[1][2]:Glossary The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. Most biological traits are under the influence of polygenes (many different genes) as well as geneenvironment interactions. Some genetic traits are instantly visible, such as eye colour or number of limbs, and some are not, such as blood type, risk for specific diseases, or the thousands of basic biochemical processes that comprise life.

Genes can acquire mutations in their sequence, leading to different variants, known as alleles, in the population. These alleles encode slightly different versions of a protein, which cause different phenotype traits. Colloquial usage of the term "having a gene" (e.g., "good genes," "hair colour gene") typically refers to having a different allele of the gene. Genes evolve due to natural selection or survival of the fittest of the alleles.

The concept of a gene continues to be refined as new phenomena are discovered.[3] For example, regulatory regions of a gene can be far removed from its coding regions, and coding regions can be split into several exons. Some viruses store their genome in RNA instead of DNA and some gene products are functional non-coding RNAs. Therefore, a broad, modern working definition of a gene is any discrete locus of heritable, genomic sequence which affect an organism's traits by being expressed as a functional product or by regulation of gene expression.[4][5]

The existence of discrete inheritable units was first suggested by Gregor Mendel (18221884).[6] From 1857 to 1864, he studied inheritance patterns in 8000 common edible pea plants, tracking distinct traits from parent to offspring. He described these mathematically as 2ncombinations where n is the number of differing characteristics in the original peas. Although he did not use the term gene, he explained his results in terms of discrete inherited units that give rise to observable physical characteristics. This description prefigured the distinction between genotype (the genetic material of an organism) and phenotype (the visible traits of that organism). Mendel was also the first to demonstrate independent assortment, the distinction between dominant and recessive traits, the distinction between a heterozygote and homozygote, and the phenomenon of discontinuous inheritance.

Prior to Mendel's work, the dominant theory of heredity was one of blending inheritance, which suggested that each parent contributed fluids to the fertilisation process and that the traits of the parents blended and mixed to produce the offspring. Charles Darwin developed a theory of inheritance he termed pangenesis, from Greek pan ("all, whole") and genesis ("birth") / genos ("origin").[7][8] Darwin used the term gemmule to describe hypothetical particles that would mix during reproduction.

Mendel's work went largely unnoticed after its first publication in 1866, but was rediscovered in the late 19th century by Hugo de Vries, Carl Correns, and Erich von Tschermak, who (claimed to have) reached similar conclusions in their own research.[9] Specifically, in 1889, Hugo de Vries published his book Intracellular Pangenesis,[10] in which he postulated that different characters have individual hereditary carriers and that inheritance of specific traits in organisms comes in particles. De Vries called these units "pangenes" (Pangens in German), after Darwin's 1868 pangenesis theory.

Sixteen years later, in 1905, the word genetics was first used by William Bateson,[11] while Eduard Strasburger, amongst others, still used the term pangene for the fundamental physical and functional unit of heredity.[12] In 1909 the Danish botanist Wilhelm Johannsen shortened the name to "gene". [13]

Advances in understanding genes and inheritance continued throughout the 20th century. Deoxyribonucleic acid (DNA) was shown to be the molecular repository of genetic information by experiments in the 1940s to 1950s.[14][15] The structure of DNA was studied by Rosalind Franklin and Maurice Wilkins using X-ray crystallography, which led James D. Watson and Francis Crick to publish a model of the double-stranded DNA molecule whose paired nucleotide bases indicated a compelling hypothesis for the mechanism of genetic replication.[16][17]

In the early 1950s the prevailing view was that the genes in a chromosome acted like discrete entities, indivisible by recombination and arranged like beads on a string. The experiments of Benzer using mutants defective in the rII region of bacteriophage T4 (1955-1959) showed that individual genes have a simple linear structure and are likely to be equivalent to a linear section of DNA.[18][19]

Collectively, this body of research established the central dogma of molecular biology, which states that proteins are translated from RNA, which is transcribed from DNA. This dogma has since been shown to have exceptions, such as reverse transcription in retroviruses. The modern study of genetics at the level of DNA is known as molecular genetics.

In 1972, Walter Fiers and his team at the University of Ghent were the first to determine the sequence of a gene: the gene for Bacteriophage MS2 coat protein.[20] The subsequent development of chain-termination DNA sequencing in 1977 by Frederick Sanger improved the efficiency of sequencing and turned it into a routine laboratory tool.[21] An automated version of the Sanger method was used in early phases of the Human Genome Project.[22]

The theories developed in the 1930s and 1940s to integrate molecular genetics with Darwinian evolution are called the modern evolutionary synthesis, a term introduced by Julian Huxley.[23] Evolutionary biologists subsequently refined this concept, such as George C. Williams' gene-centric view of evolution. He proposed an evolutionary concept of the gene as a unit of natural selection with the definition: "that which segregates and recombines with appreciable frequency."[24]:24 In this view, the molecular gene transcribes as a unit, and the evolutionary gene inherits as a unit. Related ideas emphasizing the centrality of genes in evolution were popularized by Richard Dawkins.[25][26]

The vast majority of living organisms encode their genes in long strands of DNA (deoxyribonucleic acid). DNA consists of a chain made from four types of nucleotide subunits, each composed of: a five-carbon sugar (2'-deoxyribose), a phosphate group, and one of the four bases adenine, cytosine, guanine, and thymine.[2]:2.1

Two chains of DNA twist around each other to form a DNA double helix with the phosphate-sugar backbone spiralling around the outside, and the bases pointing inwards with adenine base pairing to thymine and guanine to cytosine. The specificity of base pairing occurs because adenine and thymine align to form two hydrogen bonds, whereas cytosine and guanine form three hydrogen bonds. The two strands in a double helix must therefore be complementary, with their sequence of bases matching such that the adenines of one strand are paired with the thymines of the other strand, and so on.[2]:4.1

Due to the chemical composition of the pentose residues of the bases, DNA strands have directionality. One end of a DNA polymer contains an exposed hydroxyl group on the deoxyribose; this is known as the 3'end of the molecule. The other end contains an exposed phosphate group; this is the 5'end. The two strands of a double-helix run in opposite directions. Nucleic acid synthesis, including DNA replication and transcription occurs in the 5'3'direction, because new nucleotides are added via a dehydration reaction that uses the exposed 3'hydroxyl as a nucleophile.[27]:27.2

The expression of genes encoded in DNA begins by transcribing the gene into RNA, a second type of nucleic acid that is very similar to DNA, but whose monomers contain the sugar ribose rather than deoxyribose. RNA also contains the base uracil in place of thymine. RNA molecules are less stable than DNA and are typically single-stranded. Genes that encode proteins are composed of a series of three-nucleotide sequences called codons, which serve as the "words" in the genetic "language". The genetic code specifies the correspondence during protein translation between codons and amino acids. The genetic code is nearly the same for all known organisms.[2]:4.1

The total complement of genes in an organism or cell is known as its genome, which may be stored on one or more chromosomes. A chromosome consists of a single, very long DNA helix on which thousands of genes are encoded.[2]:4.2 The region of the chromosome at which a particular gene is located is called its locus. Each locus contains one allele of a gene; however, members of a population may have different alleles at the locus, each with a slightly different gene sequence.

The majority of eukaryotic genes are stored on a set of large, linear chromosomes. The chromosomes are packed within the nucleus in complex with storage proteins called histones to form a unit called a nucleosome. DNA packaged and condensed in this way is called chromatin.[2]:4.2 The manner in which DNA is stored on the histones, as well as chemical modifications of the histone itself, regulate whether a particular region of DNA is accessible for gene expression. In addition to genes, eukaryotic chromosomes contain sequences involved in ensuring that the DNA is copied without degradation of end regions and sorted into daughter cells during cell division: replication origins, telomeres and the centromere.[2]:4.2 Replication origins are the sequence regions where DNA replication is initiated to make two copies of the chromosome. Telomeres are long stretches of repetitive sequence that cap the ends of the linear chromosomes and prevent degradation of coding and regulatory regions during DNA replication. The length of the telomeres decreases each time the genome is replicated and has been implicated in the aging process.[29] The centromere is required for binding spindle fibres to separate sister chromatids into daughter cells during cell division.[2]:18.2

Prokaryotes (bacteria and archaea) typically store their genomes on a single large, circular chromosome. Similarly, some eukaryotic organelles contain a remnant circular chromosome with a small number of genes.[2]:14.4 Prokaryotes sometimes supplement their chromosome with additional small circles of DNA called plasmids, which usually encode only a few genes and are transferable between individuals. For example, the genes for antibiotic resistance are usually encoded on bacterial plasmids and can be passed between individual cells, even those of different species, via horizontal gene transfer.[30]

Whereas the chromosomes of prokaryotes are relatively gene-dense, those of eukaryotes often contain regions of DNA that serve no obvious function. Simple single-celled eukaryotes have relatively small amounts of such DNA, whereas the genomes of complex multicellular organisms, including humans, contain an absolute majority of DNA without an identified function.[31] This DNA has often been referred to as "junk DNA". However, more recent analyses suggest that, although protein-coding DNA makes up barely 2% of the human genome, about 80% of the bases in the genome may be expressed, so the term "junk DNA" may be a misnomer.[5]

The structure of a gene consists of many elements of which the actual protein coding sequence is often only a small part. These include DNA regions that are not transcribed as well as untranslated regions of the RNA.

Firstly, flanking the open reading frame, all genes contain a regulatory sequence that is required for their expression. In order to be expressed, genes require a promoter sequence. The promoter is recognized and bound by transcription factors and RNA polymerase to initiate transcription.[2]:7.1 A gene can have more than one promoter, resulting in messenger RNAs (mRNA) that differ in how far they extend in the 5'end.[32] Promoter regions have a consensus sequence, however highly transcribed genes have "strong" promoter sequences that bind the transcription machinery well, whereas others have "weak" promoters that bind poorly and initiate transcription less frequently.[2]:7.2Eukaryotic promoter regions are much more complex and difficult to identify than prokaryotic promoters.[2]:7.3

Additionally, genes can have regulatory regions many kilobases upstream or downstream of the open reading frame. These act by binding to transcription factors which then cause the DNA to loop so that the regulatory sequence (and bound transcription factor) become close to the RNA polymerase binding site.[33] For example, enhancers increase transcription by binding an activator protein which then helps to recruit the RNA polymerase to the promoter; conversely silencers bind repressor proteins and make the DNA less available for RNA polymerase.[34]

The transcribed pre-mRNA contains untranslated regions at both ends which contain a ribosome binding site, terminator and start and stop codons.[35] In addition, most eukaryotic open reading frames contain untranslated introns which are removed before the exons are translated. The sequences at the ends of the introns, dictate the splice sites to generate the final mature mRNA which encodes the protein or RNA product.[36]

Many prokaryotic genes are organized into operons, with multiple protein-coding sequences that are transcribed as a unit.[37][38] The genes in an operon are transcribed as a continuous messenger RNA, referred to as a polycistronic mRNA. The term cistron in this context is equivalent to gene. The transcription of an operons mRNA is often controlled by a repressor that can occur in an active or inactive state depending on the presence of certain specific metabolites.[39] When active, the repressor binds to a DNA sequence at the beginning of the operon, called the operator region, and represses transcription of the operon; when the repressor is inactive transcription of the operon can occur (see e.g. Lac operon). The products of operon genes typically have related functions and are involved in the same regulatory network.[2]:7.3

Defining exactly what section of a DNA sequence comprises a gene is difficult.[3]Regulatory regions of a gene such as enhancers do not necessarily have to be close to the coding sequence on the linear molecule because the intervening DNA can be looped out to bring the gene and its regulatory region into proximity. Similarly, a gene's introns can be much larger than its exons. Regulatory regions can even be on entirely different chromosomes and operate in trans to allow regulatory regions on one chromosome to come in contact with target genes on another chromosome.[40][41]

Early work in molecular genetics suggested the concept that one gene makes one protein. This concept (originally called the one gene-one enzyme hypothesis) emerged from an influential 1941 paper by George Beadle and Edward Tatum on experiments with mutants of the fungus Neurospora crassa.[42]Norman Horowitz, an early colleague on the Neurospora research, reminisced in 2004 that these experiments founded the science of what Beadle and Tatum called biochemical genetics. In actuality they proved to be the opening gun in what became molecular genetics and all the developments that have followed from that.[43] The one gene-one protein concept has been refined since the discovery of genes that can encode multiple proteins by alternative splicing and coding sequences split in short section across the genome whose mRNAs are concatenated by trans-splicing.[5][44][45]

A broad operational definition is sometimes used to encompass the complexity of these diverse phenomena, where a gene is defined as a union of genomic sequences encoding a coherent set of potentially overlapping functional products.[11] This definition categorizes genes by their functional products (proteins or RNA) rather than their specific DNA loci, with regulatory elements classified as gene-associated regions.[11]

In all organisms, two steps are required to read the information encoded in a gene's DNA and produce the protein it specifies. First, the gene's DNA is transcribed to messenger RNA (mRNA).[2]:6.1 Second, that mRNA is translated to protein.[2]:6.2 RNA-coding genes must still go through the first step, but are not translated into protein.[46] The process of producing a biologically functional molecule of either RNA or protein is called gene expression, and the resulting molecule is called a gene product.

The nucleotide sequence of a gene's DNA specifies the amino acid sequence of a protein through the genetic code. Sets of three nucleotides, known as codons, each correspond to a specific amino acid.[2]:6 The principle that three sequential bases of DNA code for each amino acid was demonstrated in 1961 using frameshift mutations in the rIIB gene of bacteriophage T4[47] (see Crick, Brenner et al. experiment).

Additionally, a "start codon", and three "stop codons" indicate the beginning and end of the protein coding region. There are 64possible codons (four possible nucleotides at each of three positions, hence 43possible codons) and only 20standard amino acids; hence the code is redundant and multiple codons can specify the same amino acid. The correspondence between codons and amino acids is nearly universal among all known living organisms.[48]

Transcription produces a single-stranded RNA molecule known as messenger RNA, whose nucleotide sequence is complementary to the DNA from which it was transcribed.[2]:6.1 The mRNA acts as an intermediate between the DNA gene and its final protein product. The gene's DNA is used as a template to generate a complementary mRNA. The mRNA matches the sequence of the gene's DNA coding strand because it is synthesised as the complement of the template strand. Transcription is performed by an enzyme called an RNA polymerase, which reads the template strand in the 3' to 5'direction and synthesizes the RNA from 5' to 3'. To initiate transcription, the polymerase first recognizes and binds a promoter region of the gene. Thus, a major mechanism of gene regulation is the blocking or sequestering the promoter region, either by tight binding by repressor molecules that physically block the polymerase, or by organizing the DNA so that the promoter region is not accessible.[2]:7

In prokaryotes, transcription occurs in the cytoplasm; for very long transcripts, translation may begin at the 5'end of the RNA while the 3'end is still being transcribed. In eukaryotes, transcription occurs in the nucleus, where the cell's DNA is stored. The RNA molecule produced by the polymerase is known as the primary transcript and undergoes post-transcriptional modifications before being exported to the cytoplasm for translation. One of the modifications performed is the splicing of introns which are sequences in the transcribed region that do not encode protein. Alternative splicing mechanisms can result in mature transcripts from the same gene having different sequences and thus coding for different proteins. This is a major form of regulation in eukaryotic cells and also occurs in some prokaryotes.[2]:7.5[49]

Translation is the process by which a mature mRNA molecule is used as a template for synthesizing a new protein.[2]:6.2 Translation is carried out by ribosomes, large complexes of RNA and protein responsible for carrying out the chemical reactions to add new amino acids to a growing polypeptide chain by the formation of peptide bonds. The genetic code is read three nucleotides at a time, in units called codons, via interactions with specialized RNA molecules called transfer RNA (tRNA). Each tRNA has three unpaired bases known as the anticodon that are complementary to the codon it reads on the mRNA. The tRNA is also covalently attached to the amino acid specified by the complementary codon. When the tRNA binds to its complementary codon in an mRNA strand, the ribosome attaches its amino acid cargo to the new polypeptide chain, which is synthesized from amino terminus to carboxyl terminus. During and after synthesis, most new proteins must fold to their active three-dimensional structure before they can carry out their cellular functions.[2]:3

Genes are regulated so that they are expressed only when the product is needed, since expression draws on limited resources.[2]:7 A cell regulates its gene expression depending on its external environment (e.g. available nutrients, temperature and other stresses), its internal environment (e.g. cell division cycle, metabolism, infection status), and its specific role if in a multicellular organism. Gene expression can be regulated at any step: from transcriptional initiation, to RNA processing, to post-translational modification of the protein. The regulation of lactose metabolism genes in E. coli (lac operon) was the first such mechanism to be described in 1961.[50]

A typical protein-coding gene is first copied into RNA as an intermediate in the manufacture of the final protein product.[2]:6.1 In other cases, the RNA molecules are the actual functional products, as in the synthesis of ribosomal RNA and transfer RNA. Some RNAs known as ribozymes are capable of enzymatic function, and microRNA has a regulatory role. The DNA sequences from which such RNAs are transcribed are known as non-coding RNA genes.[46]

Some viruses store their entire genomes in the form of RNA, and contain no DNA at all.[51][52] Because they use RNA to store genes, their cellular hosts may synthesize their proteins as soon as they are infected and without the delay in waiting for transcription.[53] On the other hand, RNA retroviruses, such as HIV, require the reverse transcription of their genome from RNA into DNA before their proteins can be synthesized. RNA-mediated epigenetic inheritance has also been observed in plants and very rarely in animals.[54]

Organisms inherit their genes from their parents. Asexual organisms simply inherit a complete copy of their parent's genome. Sexual organisms have two copies of each chromosome because they inherit one complete set from each parent.[2]:1

According to Mendelian inheritance, variations in an organism's phenotype (observable physical and behavioral characteristics) are due in part to variations in its genotype (particular set of genes). Each gene specifies a particular trait with different sequence of a gene (alleles) giving rise to different phenotypes. Most eukaryotic organisms (such as the pea plants Mendel worked on) have two alleles for each trait, one inherited from each parent.[2]:20

Alleles at a locus may be dominant or recessive; dominant alleles give rise to their corresponding phenotypes when paired with any other allele for the same trait, whereas recessive alleles give rise to their corresponding phenotype only when paired with another copy of the same allele. For example, if the allele specifying tall stems in pea plants is dominant over the allele specifying short stems, then pea plants that inherit one tall allele from one parent and one short allele from the other parent will also have tall stems. Mendel's work demonstrated that alleles assort independently in the production of gametes, or germ cells, ensuring variation in the next generation. Although Mendelian inheritance remains a good model for many traits determined by single genes (including a number of well-known genetic disorders) it does not include the physical processes of DNA replication and cell division.[55][56]

The growth, development, and reproduction of organisms relies on cell division, or the process by which a single cell divides into two usually identical daughter cells. This requires first making a duplicate copy of every gene in the genome in a process called DNA replication.[2]:5.2 The copies are made by specialized enzymes known as DNA polymerases, which "read" one strand of the double-helical DNA, known as the template strand, and synthesize a new complementary strand. Because the DNA double helix is held together by base pairing, the sequence of one strand completely specifies the sequence of its complement; hence only one strand needs to be read by the enzyme to produce a faithful copy. The process of DNA replication is semiconservative; that is, the copy of the genome inherited by each daughter cell contains one original and one newly synthesized strand of DNA.[2]:5.2

The rate of DNA replication in living cells was first measured as the rate of phage T4 DNA elongation in phage-infected E. coli and found to be impressively rapid.[57] During the period of exponential DNA increase at 37 C, the rate of elongation was 749 nucleotides per second.

After DNA replication is complete, the cell must physically separate the two copies of the genome and divide into two distinct membrane-bound cells.[2]:18.2 In prokaryotes(bacteria and archaea) this usually occurs via a relatively simple process called binary fission, in which each circular genome attaches to the cell membrane and is separated into the daughter cells as the membrane invaginates to split the cytoplasm into two membrane-bound portions. Binary fission is extremely fast compared to the rates of cell division in eukaryotes. Eukaryotic cell division is a more complex process known as the cell cycle; DNA replication occurs during a phase of this cycle known as S phase, whereas the process of segregating chromosomes and splitting the cytoplasm occurs during M phase.[2]:18.1

The duplication and transmission of genetic material from one generation of cells to the next is the basis for molecular inheritance, and the link between the classical and molecular pictures of genes. Organisms inherit the characteristics of their parents because the cells of the offspring contain copies of the genes in their parents' cells. In asexually reproducing organisms, the offspring will be a genetic copy or clone of the parent organism. In sexually reproducing organisms, a specialized form of cell division called meiosis produces cells called gametes or germ cells that are haploid, or contain only one copy of each gene.[2]:20.2 The gametes produced by females are called eggs or ova, and those produced by males are called sperm. Two gametes fuse to form a diploid fertilized egg, a single cell that has two sets of genes, with one copy of each gene from the mother and one from the father.[2]:20

During the process of meiotic cell division, an event called genetic recombination or crossing-over can sometimes occur, in which a length of DNA on one chromatid is swapped with a length of DNA on the corresponding homologous non-sister chromatid. This can result in reassortment of otherwise linked alleles.[2]:5.5 The Mendelian principle of independent assortment asserts that each of a parent's two genes for each trait will sort independently into gametes; which allele an organism inherits for one trait is unrelated to which allele it inherits for another trait. This is in fact only true for genes that do not reside on the same chromosome, or are located very far from one another on the same chromosome. The closer two genes lie on the same chromosome, the more closely they will be associated in gametes and the more often they will appear together; genes that are very close are essentially never separated because it is extremely unlikely that a crossover point will occur between them. This is known as genetic linkage.[58]

DNA replication is for the most part extremely accurate, however errors (mutations) do occur.[2]:7.6 The error rate in eukaryotic cells can be as low as 108 per nucleotide per replication,[59][60] whereas for some RNA viruses it can be as high as 103.[61] This means that each generation, each human genome accumulates 12 new mutations.[61] Small mutations can be caused by DNA replication and the aftermath of DNA damage and include point mutations in which a single base is altered and frameshift mutations in which a single base is inserted or deleted. Either of these mutations can change the gene by missense (change a codon to encode a different amino acid) or nonsense (a premature stop codon).[62] Larger mutations can be caused by errors in recombination to cause chromosomal abnormalities including the duplication, deletion, rearrangement or inversion of large sections of a chromosome. Additionally, DNA repair mechanisms can introduce mutational errors when repairing physical damage to the molecule. The repair, even with mutation, is more important to survival than restoring an exact copy, for example when repairing double-strand breaks.[2]:5.4

When multiple different alleles for a gene are present in a species's population it is called polymorphic. Most different alleles are functionally equivalent, however some alleles can give rise to different phenotypic traits. A gene's most common allele is called the wild type, and rare alleles are called mutants. The genetic variation in relative frequencies of different alleles in a population is due to both natural selection and genetic drift.[63] The wild-type allele is not necessarily the ancestor of less common alleles, nor is it necessarily fitter.

Most mutations within genes are neutral, having no effect on the organism's phenotype (silent mutations). Some mutations do not change the amino acid sequence because multiple codons encode the same amino acid (synonymous mutations). Other mutations can be neutral if they lead to amino acid sequence changes, but the protein still functions similarly with the new amino acid (e.g. conservative mutations). Many mutations, however, are deleterious or even lethal, and are removed from populations by natural selection. Genetic disorders are the result of deleterious mutations and can be due to spontaneous mutation in the affected individual, or can be inherited. Finally, a small fraction of mutations are beneficial, improving the organism's fitness and are extremely important for evolution, since their directional selection leads to adaptive evolution.[2]:7.6

Genes with a most recent common ancestor, and thus a shared evolutionary ancestry, are known as homologs.[64] These genes appear either from gene duplication within an organism's genome, where they are known as paralogous genes, or are the result of divergence of the genes after a speciation event, where they are known as orthologous genes,[2]:7.6 and often perform the same or similar functions in related organisms. It is often assumed that the functions of orthologous genes are more similar than those of paralogous genes, although the difference is minimal.[65][66]

The relationship between genes can be measured by comparing the sequence alignment of their DNA.[2]:7.6 The degree of sequence similarity between homologous genes is called conserved sequence. Most changes to a gene's sequence do not affect its function and so genes accumulate mutations over time by neutral molecular evolution. Additionally, any selection on a gene will cause its sequence to diverge at a different rate. Genes under stabilizing selection are constrained and so change more slowly whereas genes under directional selection change sequence more rapidly.[67] The sequence differences between genes can be used for phylogenetic analyses to study how those genes have evolved and how the organisms they come from are related.[68][69]

The most common source of new genes in eukaryotic lineages is gene duplication, which creates copy number variation of an existing gene in the genome.[70][71] The resulting genes (paralogs) may then diverge in sequence and in function. Sets of genes formed in this way comprise a gene family. Gene duplications and losses within a family are common and represent a major source of evolutionary biodiversity.[72] Sometimes, gene duplication may result in a nonfunctional copy of a gene, or a functional copy may be subject to mutations that result in loss of function; such nonfunctional genes are called pseudogenes.[2]:7.6

"Orphan" genes, whose sequence shows no similarity to existing genes, are less common than gene duplicates. Estimates of the number of genes with no homologs outside humans range from 18[73] to 60.[74] Two primary sources of orphan protein-coding genes are gene duplication followed by extremely rapid sequence change, such that the original relationship is undetectable by sequence comparisons, and de novo conversion of a previously non-coding sequence into a protein-coding gene.[75] De novo genes are typically shorter and simpler in structure than most eukaryotic genes, with few if any introns.[70] Over long evolutionary time periods, de novo gene birth may be responsible for a significant fraction of taxonomically-restricted gene families.[76]

Horizontal gene transfer refers to the transfer of genetic material through a mechanism other than reproduction. This mechanism is a common source of new genes in prokaryotes, sometimes thought to contribute more to genetic variation than gene duplication.[77] It is a common means of spreading antibiotic resistance, virulence, and adaptive metabolic functions.[30][78] Although horizontal gene transfer is rare in eukaryotes, likely examples have been identified of protist and alga genomes containing genes of bacterial origin.[79][80]

The genome is the total genetic material of an organism and includes both the genes and non-coding sequences.[81]

The genome size, and the number of genes it encodes varies widely between organisms. The smallest genomes occur in viruses (which can have as few as 2 protein-coding genes),[90] and viroids (which act as a single non-coding RNA gene).[91] Conversely, plants can have extremely large genomes,[92] with rice containing >46,000 protein-coding genes.[93] The total number of protein-coding genes (the Earth's proteome) is estimated to be 5million sequences.[94]

Although the number of base-pairs of DNA in the human genome has been known since the 1960s, the estimated number of genes has changed over time as definitions of genes, and methods of detecting them have been refined. Initial theoretical predictions of the number of human genes were as high as 2,000,000.[95] Early experimental measures indicated there to be 50,000100,000 transcribed genes (expressed sequence tags).[96] Subsequently, the sequencing in the Human Genome Project indicated that many of these transcripts were alternative variants of the same genes, and the total number of protein-coding genes was revised down to ~20,000[89] with 13 genes encoded on the mitochondrial genome.[87] Of the human genome, only 12% consists of protein-coding genes,[97] with the remainder being 'noncoding' DNA such as introns, retrotransposons, and noncoding RNAs.[97][98] Every multicellular organism has all its genes in each cell of its body but not every gene functions in every cell .

Essential genes are the set of genes thought to be critical for an organism's survival.[100] This definition assumes the abundant availability of all relevant nutrients and the absence of environmental stress. Only a small portion of an organism's genes are essential. In bacteria, an estimated 250400 genes are essential for Escherichia coli and Bacillus subtilis, which is less than 10% of their genes.[101][102][103] Half of these genes are orthologs in both organisms and are largely involved in protein synthesis.[103] In the budding yeast Saccharomyces cerevisiae the number of essential genes is slightly higher, at 1000 genes (~20% of their genes).[104] Although the number is more difficult to measure in higher eukaryotes, mice and humans are estimated to have around 2000 essential genes (~10% of their genes).[105] The synthetic organism, Syn 3, has a minimal genome of 473 essential genes and quasi-essential genes (necessary for fast growth), although 149 have unknown function.[99]

Essential genes include Housekeeping genes (critical for basic cell functions)[106] as well as genes that are expressed at different times in the organisms development or life cycle.[107] Housekeeping genes are used as experimental controls when analysing gene expression, since they are constitutively expressed at a relatively constant level.

Gene nomenclature has been established by the HUGO Gene Nomenclature Committee (HGNC) for each known human gene in the form of an approved gene name and symbol (short-form abbreviation), which can be accessed through a database maintained by HGNC. Symbols are chosen to be unique, and each gene has only one symbol (although approved symbols sometimes change). Symbols are preferably kept consistent with other members of a gene family and with homologs in other species, particularly the mouse due to its role as a common model organism.[108]

Genetic engineering is the modification of an organism's genome through biotechnology. Since the 1970s, a variety of techniques have been developed to specifically add, remove and edit genes in an organism.[109] Recently developed genome engineering techniques use engineered nuclease enzymes to create targeted DNA repair in a chromosome to either disrupt or edit a gene when the break is repaired.[110][111][112][113] The related term synthetic biology is sometimes used to refer to extensive genetic engineering of an organism.[114]

Genetic engineering is now a routine research tool with model organisms. For example, genes are easily added to bacteria[115] and lineages of knockout mice with a specific gene's function disrupted are used to investigate that gene's function.[116][117] Many organisms have been genetically modified for applications in agriculture, industrial biotechnology, and medicine.

For multicellular organisms, typically the embryo is engineered which grows into the adult genetically modified organism.[118] However, the genomes of cells in an adult organism can be edited using gene therapy techniques to treat genetic diseases.

Alberts B, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2002). Molecular Biology of the Cell (Fourth ed.). New York: Garland Science. ISBN978-0-8153-3218-3. A molecular biology textbook available free online through NCBI Bookshelf.

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