AP Biology class blog for discussing current research in Biology

Author: 12whiteal

Puberty Before She’s Ready





Precocious puberty, puberty that occurs earlier than usual, is affecting many little girls all over the country. In the article Puberty before age 10- a new ‘normal’, a 6 year old girl, Ainsley, is developing breasts, pubic hair, armpit hair and a few pimples. All of these aspects of puberty are commonly found in girls ages 12-14 but it is occuring in girls at age 6.

Precocious puberty is not only a physical issue but a big emotional problem. AInsley does not feel “normal” compared to the kids at schools. Her precoious puberty is very embarrassing for her. The western doctors don’t have an answer for Ainsley’s precocious puberty and simply accept that precocious puberty has become more rampant in America.

However, there are some answers. Precocious puberty is due to high hormone levels of estrogen. However, a lot of the time these estrogens are not from the ovaries. In fact they come from the environment. These estrogens are called xeno-estrogens. These are chemicals, insulin and sugar, that mimic estrogen; they cause minor health problems but it is a relatively knew chemical in science. The xenoestrogens are causing precocious puberty.

So has the age of puberty increased within these past years? No It has not. Puberty includes three things breast development, pubic hair growth and menstruation. Although the average age of breast development has increased in recent years the average age of menstruation has not.

There are some girls that do not have precocious puberty but start puberty earlier than other girls. However this group is beginning to get blurred together with the girls that actually have precocious puberty. The difference between these two girls is that the girls with precocious puberty will have advanced bone age. They will be shorter than a girl who starts her period later.

Although precocious puberty doesn’t seem that bad, it has negative effects for these girls socially. These girls tend to lose their virginity faster, get depression and have low self-esteem. What do you think, is precocious puberty something we should worry about?


other links:–year-old-girls/


link to article:

The Female Brain book review






Have you ever wondered why women have more friends than men? Why men allegedly do better in math than women? Or why women aren’t in alot of science and math related fields? Finally, Dr. Louann Brizendine has uncovered this mystery for us in a scientific light; the female and the male brain are not the same. Whether it is a difference in hormones or varying sections in size of certain parts of the brain, the two brains are very distinct from each other.

The bookThe Female Brain  written by Dr. Louann Brizendine, uncovers that women have larger sections of: the anterior cingulate cortex which makes decisions, the prefrontal cortex (deals with planning and some aspects of one’s personality), the insula (or the center that processes gut feelings) and the hippocampus (the long term memory storage housein the brain). Men have smaller sections of the preceding but have a larger amygdala which is responsible for emotions.  The larger it is in a certain species corresponds with the levels of aggression. In fact when males are castrated their amygdala gets smaller by thirty percent.

Dr. Brizendine uncovers that women thrive on social connections, are family oriented and can read faces, which means that a women can tell how a person is feeling by looking at his face. Men however, do not thrive on social connections and cannot read faces.

Dr. Brizendine gives an example of this with mathematical and engineering occupations. Their are not many females in those two fields; many people believed that they are not smart enough to think in such a complex way. The reality is that those two occupations are very isolated and women like to be in occupations where they can interact with people more. That is why there are many more women as lawyers and journalists than men. It is a well known fact that their are more women’s magazines than men’s magazines because women seem to flock towards these areas of occupation.

Dr. Brizendine uncovers the mysteries of the Female brain in seven insightful and entertaining chapters. The chapters go through the life of a female. Each chapter goes from the birth of the female brain  to the mature female brain. This a must read for Women and Men across the globe.

Other links:

If you want to hear a passage of the Female brain from Louann Brizendine:


Global Warming is now affecting the next Ice age

Carbon dioxide emissions in our atmosphere are not only creating global warming but are disrupting the earth’s environmental cycle. Ice ages  occur very rarely in the earths history but it is essential to the earths environmental cycle. According to a study done at Cambridge University, University College London, the University of Florida and Norway’s University of Bergen, the high levels of carbon dioxide emissions in the atmosphere has disrupted this cycle and the next ice age is delayed to at least 1500 years

An Ice Age is a period of time where the earth’s temperature is consistently low resulting in ice sheets and glaciers. Long-term reduction in the earth’s surface temperature and atmospheric temperature creates ice sheets and glaciers. The glaciers reflect the suns energy and absorb less energy. Earth is currently in an interglacial period, warm period, for 10,000 to 15,000 years.

The study was conducted at Cambridge University, University College London, the University of Florida and Norway’s University of Bergen; they used rock samples and information about the variations in the earths orbit. Through research they figured out that the next ice age will not be until 1500 years. However, it will only occur in the next 1500 years if carbon dioxide emissions do not exceed 240 ppmv and we are currently at 390 ppmv. Carbon Dioxide emissions are rising not decreasing so the next ice age might be delayed longer than 1500 years if we do not reduce carbon emissions.

Link to article

Other Links:











A New Drug Can Potentially Cure Radiation Sickness

Radiation from a major nuclear accident can kill thousands of people. It is very dangerous and depending on how much radiation people are exposed, high exposures of radtion make people get radiation  sickness and eventually they die. Radiation exposure levels up to 10 gray would require a bone marrow transplant. After exposure to radiation bone marrow is the first thing that is effected and that is where white blood cells are located and a healthy immune system is needed after exposure to radiation. Radiation can cause bacteria to leak into the blood, causing blood pressure to spike, feder, abnormal blood clotting and organ failure. A bone marrow transplant is almost necessary. However, after a major nuclear accident thousands of people will need bone marrow transplants and that might be very tricky to execute.

But there is a solution! New research has proven that a drug composed of fluoroquinolone antibiotic combined with a microbe fighting compound- a protein called BPI– can protect thousands of people from the effects of radiation. How? This antibiotic and protein can attack the bacteria that is leaked in the blood and causes all these harmful effects. The antibiotic kills the bacteria and the protein latches onto the bacterial endoxtin, a molecule on the coats of bacteria.

Researchers exposed mice to radiation for 24 hours and gave some of the mice the injections of the antibiotic and the protein. The mice who did not get the antibiotic and the protein died 30 days later.  80 percent of the mice who got the antiobiotic and the protein lived almost healthily.

This drug could change the harmful effects of radiation and could be very useful to the world as nuclear sources of energy are used more often. However, it is still in production and is not perfected. Doctor Eva Guinan  of the dana-Farber cancer institute and Harvard medical school believes that “We still have a lot more to explore in detail, but the results are really encouraging.” Do you think this future drug will completely solve the problem of radiation sickness?


other links:


original radiation sickness article

Information on Quinlone


More information on BPI


Information on Radiation poising

Information on Bone Marrow transplants

alternate article  on radiation sickness treatment


Are premature babies a precursor for autism?

At one point in history premature babies were at a high risk of mortality. They’re organs are not fully developed and they can get very sick easily. However, now the cute less than four pound babies have a lower risk of morality because of improvements in science and technology.  Nevertheless premature babies have a new problem to worry about. Current research at the University of Pennsylvania nursing school has confirmed that low birth weight has a strong connection with autism. This study was conducted between 1984 and 1987, 21 years, in certain counties in New Jersey. They followed 862 children from birth to young adults and found that five percent had autism spectrum disorders, the umbrella of autistic disorders like Aspergers disorder, Rett’s syndrome and Autistic disorder. Since some premature babies are not fully developed their brains might not have undergone full development in the cognitive and social parts of the brain.  Dr. Pinto-Martin warned the public that “If there is suspicion of autism or a positive screening test for ASD, parents shold seek an evaluation for an ASD. Early intervention improves long-term outcome and can help these children both at school and at home”.  What do you guys think? Is five percent of 832 children a good enough sign to say that premature babies and autism spectrum disorders have a link?


Other Links:

another article on premature babies and autism

Premature babies information

Information on autism spectrum disorders

more information on premature babies




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