10-1 Although mutations of the globin gene tend to occur commonly in various par
ID: 281795 • Letter: 1
Question
10-1 Although mutations of the globin gene tend to occur commonly in various parts of the world where malaria is prevalent, the specific globin mutations tend to be population- specific. Explain this in terms of population genetic theory. 10-2 characterized by progressive ataxia (unsteadiness), telangiectasias (dilated skin capillaries), immunodeficiency and predisposition to lymphomas. The frequency of AT in the population is approximately 1:40,000 individuals Ataxia telangiectasia is an autosomal recessive disorder a. It has been suggested that carriers of the AT mutant allele might have increased risk of malignancy. What is the carrier frequency of the AT gene? b. If this hypothesis were correct and AT carriers died of cancer between ages 50 and 70 years, what would this selection do to the frequency of the AT gene?Explanation / Answer
Answer 10-1
Genetic makeup of every individual is unique. There is a difference in genetic makeup of different population which had resulted through evolutionary process. For example, people residing near equator have dark complexion and those in the colder region have fair complexion. Population genetics is studied as subfield of genetics which focuses on the differences present within the population and between different populations on genetic basis. These genetic differences or mutations are sometimes essential for the survival of an individual at some particular geographical locations. For example, African population have higher rate of globin mutations compared to other populations. This is because the individuals having heterozygous alleles develops different RBC that is having resistance towards the attack of malarial parasites. Since malaria is very common in Africa, globin mutants are considered as a positive selection in these regions are played important role in the survival of African people.
Answer 10-1
a) Carrier frequency of a gene can be calculated from the incident rate as follows.
Given: incident rate of AT in a population is approximately 1/40,000. Then q2 = 1/40,000 and q = 1/400.
Since p + q = 1; therefore p = 399/400. Career frequency can therefore be calculated to be 2 x 399/100 x 1/400. Therefore, career frequency will be 0.01995 or approximately 1 in 50.
b) If this hypothesis was correct and person with this mutation died of cancer between age 50 and 70, the based on the population genetics these genes would have been lost permanently through natural selection.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.