Environment Blog 4

 The chapter of Chromosome 4 mentions pleiotropy and pluralism. It talks about how single genes do not affect a person's look but rather by other factors.The author comments on how the world is not as simple as one might think but is affected by many different factors such as fashion or nongenetic. A problem mentioned in the chapter involves "asthma," which has a direct involvement with allergies. The chapter talks about pollution and its affect on asthma and allergy. There is a theory that those whom stay away from germs and bacteria as a child are more likely to develop asthmatic systems. It is because another theory states that the bacteria found in dirt is found to trigger a part of the immune system. It also mentions why Asthma is believed to be a genetic disease in that histamines trigger the constriction of air ways which are released by mast cells.