Suppose you are a behavioral psychologist and are asked to determine to what ext
ID: 170883 • Letter: S
Question
Suppose you are a behavioral psychologist and are asked to determine to what extent intelligence (IQ) is heritable or multifactorial. That is, how much is inherited versus how much IQ results from environmental influences? How will you proceed with such a study (hint: you can take as long as you need - even a career if necessary)?
(2) Explain how nondysjunction happens and why it is so dangerous or fatal to a developing fetus. What causes Down’s syndrome and why is it one of only two survivable nondysjunction events?
(3) What is the relationship between the BRCA1/BRCA2 mutations and breast cancer? If a woman has one of these mutations, should she opt for preventative (early) mastectomy? Provide an assessment based on your knowledge of the situation.
Explanation / Answer
1) Intelligence is one of the most heritable (polygenic) behavioral traits. Intelligence increases from 20% in infancy to 80% in later adulthood. Assortative mating is also greater for the intelligence trait.
- Apart from inheritance, intelligence is also greatly influenced by the environmental influences. It is often associated with the education, social class, social mobility, health, illness and mortality differences.
- Study on intelligence behavioral trait can be done using emerging genetic designs and molecular genetics.
2) Non-dysjunction means that the chromosme pair fails to separate during the meotic division. This results in one daughter cell with extra chromosome and another daughter cell with few chromosomes.
- The most important result of this human nondysjunction is Down's syndrome (trisomy13). Nondysjunction of chromosome 21 takes place. This is the only trisomy that allows a person to live. The persons with Down's syndrome usually fare better as the developmental anamolies are not to dangerous and patients can cope up during their life time.
3) BRCA1 and BRCA2 are human genes taht produce tumor suppresor proteins. Mutations in these genes increase the risk of breast and ovarian cancers in woman. The risk of breast or ovarain cancer greatly increases if she inherits harmful muation of these genes.
- If a woman has one of these mutations, and the risk of breast cancer is more in a genetic test, then it is advisable for a preventative early mastectomy. But it entirely depends on the individual choice. mastectomy is a risk reducing surgery involving removal of both breasts.