Question 1

If the allele frequency of the dominant allele is 0.4,what value is used for the term p² in the equation p² + 2pq + q² = 1?

Accepted Answer

The term p² represents the frequency of the homozygous dominant genotype, which is calculated by squaring the frequency of the dominant allele (p). Since p = 0.4, p² = 0.4² = 0.16.

Question 2

How does inbreeding affect the Hardy-Weinberg equilibrium?

Accepted Answer

Inbreeding increases the frequency of homozygous genotypes, both dominant and recessive, in a population. This disrupts the Hardy-Weinberg equilibrium, where the frequency of homozygotes and heterozygotes should remain constant from generation to generation.

Question 3

If in a population the rate of mutation that converts the A allele to the a allele is 10⁻⁶ and the current frequency of the A allele is 0.75 and the a allele is 0.25,then the frequency of the A and a alleles in the next generation will be

Accepted Answer

The frequency of the A allele decreases slightly due to mutation, calculated as 0.75 - (0.75 * 10⁻⁶), resulting in approximately 0.7499993 for A and 0.2500007 for a.

Question 4

The mechanism that results in a change in allele frequencies due to random processes is known as

Accepted Answer

Genetic drift refers to the random fluctuations in allele frequencies in small populations that can occur by chance and can drive evolution over time.

Question 5

Microevolution is defined as

Accepted Answer

Microevolution refers to the changes in the gene pool of a population over time, such as changes in allele frequencies, that occur from one generation to the next. This can be influenced by factors such as mutation, genetic drift, migration, and natural selection.

Question 6

Horizontal gene transfer occurs

Accepted Answer

Horizontal gene transfer can occur both within and between species of eukaryotes and prokaryotes through mechanisms such as transformation, transduction, and conjugation. It is not limited to prokaryotic species only, nor is it only from prokaryotes to eukaryotes; it can also occur between eukaryotic species.

Question 7

Consider a hypothetical gene B for which there are two alleles in the population.For every ten BB individuals that survive,six Bb individuals survive,and one bb individual survives.What are the relative fitness values for each genotype?

Accepted Answer

The relative fitness values for each genotype can be calculated by dividing the survival rate of each genotype by the survival rate of the genotype with the highest fitness. In this case, BB has the highest survival rate of 10/10 = 1.0, so the relative fitness values are:

wBB = 1.0/1.0 = 1.0
wBb = 6/10 = 0.6
wbb = 1/10 = 0.1

Therefore, the correct answer is A.

Question 8

A population with an allele for a gene that constitutes 99% of the alleles in the population means that the population is called monomorphic for that gene.

Accepted Answer

Monomorphic means having only one form or allele present in a population, which is the case when one allele constitutes 99% of the alleles in the population.

Question 9

Repetitive sequences are useful for DNA fingerprinting because they

Accepted Answer

Repetitive sequences are useful for DNA fingerprinting because they are inherited and can show significant variability between individuals. These repetitive sequences, also known as variable number tandem repeats (VNTRs), are longer stretches of DNA that contain multiple copies of a short repeating sequence. The number of repeats can vary between individuals, and these variations can be used to create a unique DNA profile for each individual. However, while VNTRs can show significant variability between individuals, they are also stable enough to be reliably detected and analyzed through DNA testing. In contrast, option A is incorrect because repetitive sequences are inherited and can be passed down from parents to offspring. Option B is also incorrect because while VNTRs are unique to every individual, they do not change from generation to generation. Option D is incorrect because all DNA sequences have the potential to undergo mutation, although the rate and types of mutations can vary.

Question 10

You are preparing to perform DNA fingerprinting by PCR for the first time.Select the reagent that would result in complications in the interpretation of your results.

Accepted Answer

PCR primers that anneal to the repetitive region of the microsatellites would result in complications because they could produce a complex pattern of amplification products due to the variability in the number of repeats within the microsatellites, making interpretation difficult. Primers are ideally designed to anneal to sequences flanking the target region to ensure consistent amplification of the region of interest.

Question 11

At equilibrium the allelic and genotypic frequencies of a population change over time.

Accepted Answer

At equilibrium, both allelic and genotypic frequencies remain constant and do not change over time.

Question 12

Which term describes all the alleles of every gene in the population?

Accepted Answer

The term "gene pool" describes all the alleles of every gene in a population. It includes all the genetic information present in the population, including variations and polymorphisms. Conglomerate is not a term commonly used in genetics. Polymorphisms refer to the existence of multiple forms of a gene in a population. Genotype frequency is the proportion of individuals in a population with a particular genotype.

Question 13

The probability that a gene will be altered by a mutation is called the mutation rate.

Accepted Answer

The statement is true.

Question 14

Select the definition of genetic drift.

Accepted Answer

Genetic drift refers to the random fluctuations in the frequency of alleles in a population, often due to chance events such as a small group of individuals separating from a larger population (known as the founder effect) or the random death or reproduction of individuals. Migration (option B) can certainly affect allele frequencies, but it is a distinct mechanism from genetic drift. Changes in genotype frequencies due to new mutations (option C) can lead to changes in allele frequencies over time, but genetic drift specifically refers to changes in existing alleles in a population rather than the emergence of new ones. Finally, changes in genome size (option D) can also occur due to mutations, but they are not necessarily related to genetic drift.

Question 15

Mutations represent

Accepted Answer

Mutations are an essential part of microevolution as they provide genetic variation that natural selection acts upon, leading to changes in a population over time.

Question 16

The prevalence of the allele for sickle cell anemia in some populations is an example of which of the following?

Accepted Answer

The prevalence of the sickle cell allele in some populations is an example of balancing selection, as carriers of one copy of the allele have increased resistance to malaria, while individuals homozygous for the allele have sickle cell anemia, a potentially lethal condition. This results in the maintenance of the allele in the population through natural selection.

Question 17

If two individuals of a population,who vary in their phenotype,preferentially mate,it is called ________.

Accepted Answer

The answer of If two individuals of a population,who vary...

Question 18

Calculate the inbreeding coefficient of an individual given an n of 4 (excluding the inbred offspring)with one common ancestor. The inbreeding of the common ancestor is unknown.

Accepted Answer

To calculate the inbreeding coefficient, we need to use the formula:  F = (1/2)^(n+1)

where n is the number of meioses (generations) from the common ancestor to the individual, excluding any meioses involving inbreeding.

In this case, n=4. So, we have:

F = (1/2)^(4+1) = 1/2^5 = 1/32 = 0.03125

Therefore, the inbreeding coefficient is 3.125%, which corresponds to choice C.

Question 19

Which of the following is NOT an assumption of the Hardy-Weinberg equation?

Accepted Answer

The Hardy-Weinberg equation assumes random mating, meaning that individuals mate with each other regardless of their genotype. Nonrandom mating, such as assortative mating (where individuals choose mates based on their genotype), can cause changes in genotype frequencies and violate the assumptions of the equation.

Question 20

Match between columns
                        Premises: Exons of preexisting genes are rearranged to make a new combination
Genes from one species introduced into another species
Recombination to produce new combinations of alleles
Increase or decrease in the number of repetitive sequences
Production of hybrid offspring
Independent segregation of different homologous chromosomes gives rise to new combinations of alleles
Chromosome structure changed by deletion, duplications, inversions, translocations or there is a change in ploidy
Conjugation, transduction and transformation
Point mutations, small deletions and insertions
Additional copies of a gene occur through misaligned crossing over

Accepted Answer

The Answer of interspecies crosses and gene duplications and horizontal is...

Quiz 23: Population Genetics

If the allele frequency of the dominant allele is 0.4,what value is used for the term p² in the equation p² + 2pq + q² = 1?