Question 1

Why did the alleles that conferred insecticide resistance in mosquitoes become less frequent in the population when insecticide application was discontinued in the 1960s in Thailand?

Accepted Answer

A)  The mosquitoes experienced a bottleneck and by chance the surviving insects had a low proportion of resistance alleles.
B)  The resistance alleles were linked to a body color variation that led to resistant mosquitoes experiencing a higher rate of predation.
C)  A mosquito population with a low proportion of resistant alleles migrated to Thailand and interbred with the original population.
D)  In the absence of pesticide, mosquitos homozygous for the resistance alleles had lower fitness than the other genotypes.

Question 2

Why is the Hardy-Weinberg equation more accurate in predicting genotypic frequencies in the short run than in the long run?

Accepted Answer

A)  The equation does not take epistasis into consideration.
B)  The Hardy-Weinberg equation is based on Mendel's second law of inheritance.
C)  The equation can be applied only to traits determined by single genes.
D)  Populations do not conform to the assumptions of the Hardy-Weinberg law.

Question 3

In forensics, a DNA sample is analyzed to determine which alleles of 13 SSR loci are present.How is the probability of that specific combination of SSR alleles existing in the population calculated?

Accepted Answer

A)  The frequency of each genotype is known from determining which allele is the rarest for each locus and then determining if the individual sample contains those alleles.
B)  The total number of alleles for all loci in the population is calculated.
C)  The Hardy-Weinberg Law is used to predict the genotype frequency at each locus.
D)  The total number of alleles in the population is multiplied by 2.

Question 4

A large population of fish live in a lake. The color of their scales is determined by two different alleles of the S gene, S1 and S2. Homozygous S1 fish have yellow scales, S2 homozygotes have blue scales, and heterozygotes are green. Scientists catch 100 fish at random and record their color. Among those 100 fish are 30 yellow, 50 blue, and 20 green ones.

After the original sample is analyzed, an asteroid landed in the lake and killed all the fish that happened to be in one location. When 100 fish were sampled again, 15 were yellow, 75 were blue, and 10 were green.

-What is the frequency of the S1 allele in the population before the asteroid hit?

Accepted Answer

A)  0.15
B)  0.40
C)  0.50
D)  0.60
E)  0.80

Exam 21: Variation and Selection in Populations

Correct Answer
verified

In forensics, a DNA sample is analyzed to determine which alleles of 13 SSR loci are present.How is the probability of that specific combination of SSR alleles existing in the population calculated?

Correct Answer
verified

Why did the alleles that conferred insecticide resistance in mosquitoes become less frequent in the population when insecticide application was discontinued in the 1960s in Thailand?

Correct Answer
verified

Why is the Hardy-Weinberg equation more accurate in predicting genotypic frequencies in the short run than in the long run?

Correct Answer
verified

Exam 21: Variation and Selection in Populations

Correct AnswerverifiedShow Answer

In forensics, a DNA sample is analyzed to determine which alleles of 13 SSR loci are present.How is the probability of that specific combination of SSR alleles existing in the population calculated?

Correct AnswerverifiedShow Answer

Why did the alleles that conferred insecticide resistance in mosquitoes become less frequent in the population when insecticide application was discontinued in the 1960s in Thailand?

Correct AnswerverifiedShow Answer

Why is the Hardy-Weinberg equation more accurate in predicting genotypic frequencies in the short run than in the long run?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified