Question 1

Lifetime fitness,as demonstrated by Cummings et al.'s work on sunflowers,is dependent on what two components?

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The answer of Lifetime fitness,as demonstrated by Cummings et al.'s...

Question 2

Consider a sample of 100 individuals sampled from a population in Hardy-Weinberg equilibrium that are genotyped at a single locus.Of these 100 individuals,25 individuals are A₁A₁ homozygotes,45 are A₁A₂ heterozygotes,and 30 are A₂A₂ homozygotes.List the observed and expected genotypic frequencies of this locus in this sample.

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The answer of Consider a sample of 100 individuals sampled...

Question 3

In the following figure,m is the mutation rate from allele A₁,which produces a functional protein,to A₂,an allele that fails to produce a functional protein.The reverse mutation rate,n,describes the mutation rate from A₂,the nonfunctioning allele,to A₁,the functional protein allele.Why would one expect the value of m to be much higher than the value of n at this locus?

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The answer of In the following figure,m is the mutation...

Question 4

Mating preferences drive assortative mating

Accepted Answer

Mating preferences can play a role in assortative mating, but it is not the only factor. Other factors such as geographic proximity and social factors can also contribute to assortative mating. Therefore, mating preferences drive assortative mating only some of the time.

Question 5

Consider a locus in which the fitness of AA and Aa genotypes are greater than the fitness of aa genotype.In addition,this locus experiences forward mutation from the A allele to a allele.At this locus,the A allele will

Accepted Answer

Since the fitness of AA and Aa genotypes are greater than the fitness of aa genotype, the A allele will be selected for and increase in frequency within the population. However, the presence of forward mutation from A to a allele means that aa genotype could still arise. As aa genotype has lower fitness, it is likely to be selected against and decrease in frequency, but the A allele may not reach 100% frequency (i.e. fixation) because the a allele can still be produced via mutation. Therefore, the A allele will never go to fixation.

Question 6

What is the frequency of homozygous individuals in a Hardy-Weinberg population that experiences inbreeding expressed in terms of the frequencies of alleles (p,q)and the value of F.

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The answer of What is the frequency of homozygous individuals...

Question 7

Disassortative mating may be beneficial because

Accepted Answer

Disassortative mating, where individuals choose mates with dissimilar traits, can reduce the expression of deleterious recessive traits by increasing the frequency of heterozygotes. It can also maximize genetic diversity in offspring by bringing together different sets of alleles. However, it does not necessarily make it easier to find a mate, so option C is incorrect. Therefore, the correct answer is D, that is, choices A and B are correct.

Question 8

In pocket mice,possession of the D allele at the Mc1R locus confers dark coloration and homozygous d individuals are light in color.Why would one expect to see more D alleles in a population living on lava?

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The answer of In pocket mice,possession of the D allele...

Question 9

List five assumptions of the Hardy-Weinberg equilibrium.

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The answer of List five assumptions of the Hardy-Weinberg equilibrium....

Question 10

After one generation of inbreeding,one would expect to see a(n)_________ in heterozygotes but no change in _________ frequencies.

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The answer of After one generation of inbreeding,one would expect...

Question 11

Inbreeding depression is caused by

Accepted Answer

Inbreeding depression is caused by the increased expression of deleterious recessive alleles due to close mating between related individuals. This reduces fitness and leads to a decrease in population viability. Random mating and mutation-selection balance are not directly involved in inbreeding depression, although they may affect genetic diversity and the frequency of deleterious alleles in a population.

Question 12

What is the term for the condition in which the heterozygote is more fit than either homozygote?

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The answer of What is the term for the condition...

Question 13

Two gene copies are identical by descent if

Accepted Answer

Two gene copies are identical by descent if they are both inherited from the same gene copy in a recent common ancestor. This means that the gene has been passed down through multiple generations without any mutations or recombination events that would have created different versions (alleles) of the gene.

Question 14

What phenomenon is represented in the following figure?

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The answer of What phenomenon is represented in the following...

Question 15

When Takata et al.2002 examined allele and genotype frequencies at the myoglobin locus in a Japanese population,the observed and expected genotypic frequencies were very similar.Had they been very different,what could one conclude about this locus in this population?

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The answer of When Takata et al.2002 examined allele and...

Question 16

Pacific salmon hatch in streams and grow up out in the Pacific Ocean.At the end of their life,they mate once then die.Assuming that not all salmon survive life in the ocean and that those who do survive produce equal numbers of offspring,this would be an example of _________ selection.

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The answer of Pacific salmon hatch in streams and grow...

Question 17

Consider a human illness in which individuals homozygous for a deleterious,recessive allele suffer from a disease with a selection coefficient of s = 0.85 (i.e.,a relative fitness of 0.15).At equilibrium,the nondeleterious allele has a population frequency of 0.95.What is the mutation rate from the healthy allele to the deleterious allele?

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The answer of Consider a human illness in which individuals...

Question 18

As the value of F increases,so does the frequency of

Accepted Answer

As the inbreeding coefficient (F) increases, the frequency of homozygotes increases due to increased likelihood of inheriting identical alleles from both parents.

Question 19

Name three predictions generated from the Hardy-Weinberg model.

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The answer of Name three predictions generated from the Hardy-Weinberg...

Question 20

In the figure below,what will be the equilibrium frequency of A₁ on the island?

Accepted Answer

Equilibrium frequency is defined as the frequency at which the allelic frequency remains constant. 
For this to happen, the frequency of the dominant allele (A₁) should be greater than the frequency of the recessive allele (A₂). 
Looking at the figure, we can see that A₁ has a frequency of 0.7 and A₂ has a frequency of 0.3. 
Therefore, the equilibrium frequency for A₁ on the island is 0.7. 
Thus, choice B is the correct answer.

Quiz 7: The Genetics of Populations