Sickle cell disease (SCD) is found in numerous populations whose ...

Question

Sickle cell disease (SCD) is found in numerous populations whose ancestral homes are in the malaria belt of Africa and Asia. SCD is an autosomal recessive disorder that results from homozygosity for a mutant β-globin gene allele. Data on one affected population indicates that approximately 8 in 100 newborn infants have SCD.

What are the frequencies of the wild-type (βᴬ) and mutant (βˢ) alleles in this population?

Accepted Answer

Hello everyone and welcome to today's video. So assume that sickle cell anemia, a recessive condition affects about 10 in African American babies in the United States. So we need to estimate the frequency of the recessive or case S in the population. So as answer choice A we have 0.1 as answer choice B, we have 0.90 as answer choice C we have 0.10 and as answer choice D we have 0.81. Now, in order to solve this problem, we need to recall the Hardy Weinberg equation which is going to be P square plus two P Q plus Q square is going to be equal to one. Now, recall from the problem that sco cell anemia is stated to be a recessive condition. Therefore, these 10 in 1000 babies is going to be the frequency of the homo cycles recessive genotype in the population. Now this is going to be Q square in the Hardy Weinberg equation. Now, if we find the square root of both sides, we're going to see that Q is going to be equal to 0. and Q is going to be the frequency of the recessive A or how the problem calls it lower case S in the population. So the frequency of the recessive A S is going to be 0.10, which is represented by answer choice, C 0.10. I really hope this helped and I hope to see you on the next video.

My Courses

Chemistry

Biology

Math

Physics

Business

Social Sciences

Programming

Product & Marketing