HETEROZYGOTE ADVANTAGE


Website:
http://www.answers.com/topic/heterozygote-advantage
http://www.bookrags.com/research/heterozygote-advantage-gen-02/

Heterozygote advantage is basically an advantage obtained by only the Heterozygote genotype, which is more beneficial than the homozygous recessive and homozygous dominant. There are specific advantages and disadvantages associated with Heterozygote advantage. The most well known case of Heterozygote advantage is evident in sickle cell anemia. It is essential to know that the homozygous versions are always at disadvantages, as opposed to the heterozygous version, which can either pose an advantage or disadvantage. This also aids in explaining genetic variability.

Sickle cell anemia is a genetic disorder, which basically makes the red blood cells become sickle-shaped due to low oxygen conditions, which alter the shape of the red blood cells. This can lodge these red blood cells into capillaries, which deprives areas of the body from oxygen, which is dangerous. When a person is heterozygous for sickle cell anemia, they have a resistant to malaria. Africa is an area, in which this form of Heterozygote advantage is at work. If they were homozygous recessive they would die of sickle cell anemia, and if they were homozygous dominant they would die of malaria. Therefore, Heterozygote advantage gives many people a change in sustaining life, amidst the dangerous malaria. Another Heterozygote advantage is present in cystic fibrosis. Cystic fibrosis is basically an autosomal recessive disease, which causes mucus to form in the lungs, which is dangerous. However, it shows resistance to cholera, which was a dangerous disease plaguing the Europeans. Well cystic fibrosis can aid in sustaining life for anyone inflicted with a disease pertaining to the loss of body fluid. Thus, Heterozygote advantage is a very interesting area of biology, in which more study is needed. We can hopefully find out more diseases, which have some form of resistance to even deadlier diseases.

external image malaria_distribution.gif
http://www.biotopics.co.uk/malaria/malaria_distribution.gif
external image cystic_fibrosis.jpg
http://www.medicalook.com/diseases_images/cystic_fibrosis.jpg