Question 1

In biallelic populations,where allelic frequencies are indicated by p and q,the resultant genotype frequencies are indicated by what algebraic formula?

Accepted Answer

p² + 2pq + q²

Question 2

The Hardy-Weinberg equilibrium principle is often referred to as the ________,[two words] which indicates that if a population is in Hardy-Weinberg equilibrium,that population is not evolving.

Accepted Answer

null model

Question 3

An analysis showing the heterozygote superiority of the ΔF508 allele of CFTR demonstrates increased resistance to infections with the bacteria that cause ________.

Accepted Answer

The ΔF508 allele of CFTR is associated with increased resistance to typhoid fever, as the bacteria causing typhoid fever, Salmonella typhi, uses the CFTR protein to enter intestinal cells. Heterozygotes may have a selective advantage in areas where typhoid fever is prevalent.

Question 4

If a population is in Hardy-Weinberg equilibrium,which of the following statements is correct?

Accepted Answer

If a population is in Hardy-Weinberg equilibrium, allele frequencies must remain constant from generation to generation. This is one of the fundamental assumptions of Hardy-Weinberg equilibrium. Choices A, B, C, and E are incorrect because they do not accurately describe the conditions required for Hardy-Weinberg equilibrium.

Question 5

The null hypothesis,which demonstrates that evolution is not occurring from generation to generation,is known as the ________ model.

Accepted Answer

The null hypothesis that evolution is not occurring from generation to generation is known as the Hardy-Weinberg model. This model assumes that a population is in genetic equilibrium and that frequencies of alleles and genotypes will remain constant from generation to generation in the absence of evolutionary forces.

Question 6

A group of interbreeding individuals and their offspring is known as a(n)________.

Accepted Answer

The answer of A group of interbreeding individuals and their...

Question 7

A hypothetical population has two alleles for a gene: A and a.In a random sample of 100 individuals,20 are homozygous for a,20 are homozygous for A,and 60 are heterozygous.What is the frequency of A?

Accepted Answer

The frequency of allele A can be calculated by adding the frequency of homozygous AA individuals (20 individuals, each contributing two A alleles) and half the frequency of heterozygous Aa individuals (60 individuals, each contributing one A allele) out of the total number of alleles. This gives (20*2 + 60*1) / (100*2) = 100 / 200 = 0.5 or 50%.

Question 8

In the mating of an Aa female and an Aa male,the genotypic outcome predicted by a Punnett square is ________.

Accepted Answer

When an Aa female and an Aa male mate, their Punnett square would look like:
 
 | A | a
--|---|--
A | AA| Aa
a | Aa| aa

From this, we can see that there is a 25% chance of getting AA offspring, a 50% chance of getting Aa offspring, and a 25% chance of getting aa offspring. Therefore, the genotypic outcome predicted by a Punnett square is one-quarter AA, one-quarter aa, and one-half Aa.

Question 9

In large populations,the Hardy-Weinberg equilibrium principle can be used to determine whether evolution is occurring.For instances where allelic frequencies are indicated by p and q,the resultant genotype frequencies are indicated by which of the following equations?

Accepted Answer

The correct equation for genotype frequencies in the Hardy-Weinberg equilibrium principle is p² + 2pq + q². This equation accounts for the three possible genotype combinations: homozygous dominant (p²), homozygous recessive (q²), and heterozygous (2pq). Option A (p² + q²) only accounts for homozygous genotypes and option B (p² + pq + q²) does not distinguish between heterozygotes and homozygous recessive genotypes. Option D (p² + (pq)² + q²) is not a correct equation for the genotype frequencies in the Hardy-Weinberg equilibrium principle.

Question 10

Chun-Hong Chen and colleagues (2007)designed a new gene that would carry a strong selective advantage and confer the resistance to malaria on free-living mosquitoes.The gene was termed Medea,and this acronym stands for which of the following?

Accepted Answer

Medea stands for Maternal-effect dominant embryonic arrest, which is a genetic system designed to spread specific genes through populations.

Question 11

If there were a high allele frequency for the CCR5-32 coreceptor,and the rate of infection with HIV was high as well,one would expect the frequency of the CCR5-32 coreceptor allele to ________.

Accepted Answer

The CCR5-32 coreceptor allele has been shown to confer resistance to HIV infection. Therefore, if there is a high frequency of this allele in a population with a high rate of HIV infection, natural selection should favor individuals with this allele, leading to a rapid increase in its frequency.

Question 12

Cystic fibrosis is one of the most common genetic diseases among individuals of European ancestry,and affects one newborn in approximately how many?

Accepted Answer

Cystic fibrosis affects approximately one newborn in every 2,500 births among individuals of European ancestry, making it one of the most common life-shortening genetic diseases in this population.

Question 13

In experiments with laboratory populations of Drosophila melanogaster,Mukai and Burdick (1959)observed that a lethal allele maintained a higher than expected frequency.The explanation for this observation is that,at equilibrium,the selective advantage of the lethal allele when it occurs in heterozygotes balances the disadvantage of the allele in homozygotes,and is termed ________.

Accepted Answer

Overdominance is the phenomenon where a heterozygote has a greater fitness advantage than either of the corresponding homozygotes, leading to the maintenance of genetic variation of the allele. In this case, the lethal allele has a fitness advantage as a heterozygote, balancing the fitness disadvantage as a homozygote, resulting in the higher-than-expected frequency at equilibrium.

Question 14

The statistical test used to determine whether the quantitative allele frequency results of an experiment fall within reasonable limits,or whether the null hypothesis is violated and the measured outcomes are significantly different than those expected is called the ________.[three words]

Accepted Answer

The answer of The statistical test used to determine whether...

Question 15

Cystic fibrosis is caused by a recessive loss-of-function mutation that encodes a protein called the ________.

Accepted Answer

Cystic fibrosis is caused by a mutation in the CFTR (cystic fibrosis transmembrane conductance regulator) gene, which encodes the CFTR protein. This protein is responsible for regulating the movement of chloride ions in and out of cells, and mutations in CFTR lead to the buildup of thick mucus in the lungs, pancreas, and other organs, resulting in the classic symptoms of cystic fibrosis. Choices A, B, and D are incorrect because they do not accurately name the protein that is affected by the CFTR gene mutation.

Question 16

The point at which the rate that a deleterious allele is being eliminated from a population by natural selection is in equilibrium with the rate at which the deleterious allele is being replaced by a new mutation is termed ________.

Accepted Answer

This is the classic definition of mutation-selection balance, where the negative selective pressure against a deleterious allele is balanced by the positive pressure of recurrent mutation. This equilibrium point is important for understanding the persistence of genetic variation and the evolution of complex genetic traits. The other choices (A, B, and C) are not accurate descriptions of this concept.

Question 17

The Hardy-Weinberg equilibrium principle is known as the null hypothesis.List the five assumptions that are required for a population to be in Hardy-Weinberg equilibrium.

Accepted Answer

The answer of The Hardy-Weinberg equilibrium principle is known as...

Question 18

The probability that two mutually exclusive events will occur is calculated by ________.

Accepted Answer

The probability of mutually exclusive events occurring is calculated by adding the probability of each individual event since they cannot occur simultaneously. Multiplying the probabilities of each individual event would give the probability of both events occurring together, which is not possible in the case of mutually exclusive events. The other options are also incorrect.

Question 19

In the study of Gigord and colleagues using Elderflower orchids,the allele frequencies of yellow and purple flowers varied such that when the yellow allele started to become rare,the reproductive success of purple flowers decreased and the reproductive success of yellow-flowered individuals increased in a process known as ________.

Accepted Answer

The described process is known as frequency-dependent selection, where the fitness of a particular allele or phenotype depends on its frequency in the population. As the yellow allele became rare, it experienced a fitness advantage, while the purple allele had decreased reproductive success. This is an example of negative frequency-dependent selection, where the fitness of a phenotype decreases as its frequency in the population increases.

Question 20

Cavener and Clegg (1981)demonstrated natural selection by observing the cumulative change in allele frequencies in populations of Drosophila melanogaster that were subjected to high levels of ________.

Accepted Answer

Cavener and Clegg subjected populations of Drosophila melanogaster to high levels of alcohol, which acted as a selective pressure for individuals with higher alcohol tolerance. This led to a cumulative change in allele frequencies over time, demonstrating natural selection in action.

Quiz 6: Mendelian Genetics in Populations I: Selection and Mutation