AP BIOLOGY

EVOLUTION

EVOLUTION OF A POPULATION

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Cystic fibrosis is a recessive condition that affects about 1 in 2, 500 babies in the Caucasian population of the United States. Calculate the frequency of heterozygous individuals (carriers) in the U.S. population. Give your answer as a decimal to the nearest hundredth.
A
.98
B
.06
C
.02
D
.04
Explanation: 

Detailed explanation-1: -Cystic fibrosis is a recessive condition that affects about 1 in 2, 500 babies in the Caucasian population of the United States. Please calculate the following. The frequency of the recessive allele in the population. Answer: We know from the above that q2 is 1/2, 500 or 0.0004.

Detailed explanation-2: -Cystic fibrosis is an autosomal recessive disease. According to Hardy Weinberg Equilibrium, the frequency of an autosomal recessive disease in a population is q2, which in this case = 1/2500 and thus q = 1/50. Because the frequency of the two alleles (p & q ) must equal 1, p = 49/50   1.

Detailed explanation-3: -For example, the allele frequency of the mutant cystic fibrosis allele among Caucasians is 0.025, while the frequency of the normal allele is 0.975. This affects how alleles are distributed among an entire population.

Detailed explanation-4: -Frequency. Cystic fibrosis is a common genetic disease within the white population in the United States. The disease occurs in 1 in 2, 500 to 3, 500 white newborns. Cystic fibrosis is less common in other ethnic groups, affecting about 1 in 17, 000 African Americans and 1 in 31, 000 Asian Americans.

Detailed explanation-5: -Approximately 1 out of every 2, 500 Caucasians in the United States is born with the recessive disease cystic fibrosis.

There is 1 question to complete.