Question 1

Ronald Fisher developed a critical idea for the modern synthesis of Darwin and Mendel. What is the basis of this synthesis?

Accepted Answer

A) Mendel was correct in that most traits are discrete. 
B) Multiple genes can explain the continuous nature of most observed traits. 
C) Darwin was incorrect on how natural selection influences discrete traits like Mendel observed. 
D) Mendel and Darwin both missed the importance of population growth as described by Malthus. 
A) Mendel was correct in that most traits are discrete. 
B) Multiple genes can explain the continuous nature of most observed traits. 
C) Darwin was incorrect on how natural selection influences discrete traits like Mendel observed. 
D) Mendel and Darwin both missed the importance of population growth as described by Malthus.

Question 2

You have a small population of beetles. One day a large rainstorm causes flooding and wipes out 87% of the population. The remaining individuals have much lower genetic variation than the original population. Which of the following would explain the lack of Hardy-Weinberg equilibrium seen after the flood?

Accepted Answer

A) founder effect 
B) random mating 
C) small population size 
D) genetic drift 
E) migration 
A) founder effect 
B) random mating 
C) small population size 
D) genetic drift 
E) migration

Question 3

Hardy-Weinberg can predict genotype frequencies from _____ frequencies.

Accepted Answer

A) allele 
B) advantageous mutation 
C) deleterious mutation 
D) chromosome 
E) phenotype 
A) allele 
B) advantageous mutation 
C) deleterious mutation 
D) chromosome 
E) phenotype

Question 4

Which of the following statements is TRUE regarding the tail of a male peacock?

Accepted Answer

A) It functions in intersexual selection and helps a male peacock to attract a mate. 
B) It functions in intrasexual selection and serves a similar role as the antlers of male deer. 
C) The tail of the male peacock is relatively energetically inexpensive to produce. 
D) Sexual selection has played a minimal role, if any, in the development of the peacock tail. 
E) It functions in both intersexual and intrasexual selection. 
A) It functions in intersexual selection and helps a male peacock to attract a mate. 
B) It functions in intrasexual selection and serves a similar role as the antlers of male deer. 
C) The tail of the male peacock is relatively energetically inexpensive to produce. 
D) Sexual selection has played a minimal role, if any, in the development of the peacock tail. 
E) It functions in both intersexual and intrasexual selection.

Question 5

Both Charles Darwin and Alfred Russel Wallace acknowledged the influence of the economist Thomas Malthus in the development of their ideas about natural selection. Specifically, Malthus's ideas about geometric population growth implied that:

Accepted Answer

A) resources in every generation would be limited, therefore individuals in every generation would have to compete for those resources. 
B) only the largest and strongest individuals would survive. 
C) organisms should have as many offspring as possible. 
D) organisms should have a few, very fit offspring who can compete for scarce resources. 
E) All of these choices are correct. 
A) resources in every generation would be limited, therefore individuals in every generation would have to compete for those resources. 
B) only the largest and strongest individuals would survive. 
C) organisms should have as many offspring as possible. 
D) organisms should have a few, very fit offspring who can compete for scarce resources. 
E) All of these choices are correct.

Question 6

In a population of Mendel's garden peas, the frequency of green-flowered plants (genotype aa) is 49%. The population is in Hardy-Weinberg equilibrium. What are the frequencies of the AA and Aa genotypes?

Accepted Answer

A) 49% AA, 2% Aa 
B) 9% AA, 42% Aa 
C) 42% AA, 9% Aa 
D) 33% AA, 18% Aa 
E) The frequencies cannot be determined from the information provided. 
A) 49% AA, 2% Aa 
B) 9% AA, 42% Aa 
C) 42% AA, 9% Aa 
D) 33% AA, 18% Aa 
E) The frequencies cannot be determined from the information provided.

Question 7

Which of the following is NOT a condition of the Hardy-Weinberg equilibrium?

Accepted Answer

A) The size of a population must be large. 
B) Mating within a population must be random. 
C) Individuals can migrate in and out of a population, as long as the population size remains constant. 
D) Individuals of any genotype must have the same reproductive success as individuals of any other genotype. 
E) Mutations cannot occur in a population. 
A) The size of a population must be large. 
B) Mating within a population must be random. 
C) Individuals can migrate in and out of a population, as long as the population size remains constant. 
D) Individuals of any genotype must have the same reproductive success as individuals of any other genotype. 
E) Mutations cannot occur in a population.

Question 8

From an evolutionary perspective, germ-line mutations are more significant than somatic mutations. This is because:

Accepted Answer

A) somatic mutations affect only one or a few cells. 
B) somatic mutations are generally harmful. 
C) only germ-line mutations will appear in an individual's descendants. 
D) only germ-line mutations are potentially beneficial. 
E) somatic mutations affect only one or a few cells and only germ-line mutations will appear in an individual's descendants. 
A) somatic mutations affect only one or a few cells. 
B) somatic mutations are generally harmful. 
C) only germ-line mutations will appear in an individual's descendants. 
D) only germ-line mutations are potentially beneficial. 
E) somatic mutations affect only one or a few cells and only germ-line mutations will appear in an individual's descendants.

Question 9

Hammer-head bats are a species of African fruit bat. During the breeding season, males gather in mating arenas, where they display to females who pass through and assess males before selecting individuals with which to mate. This is an example of _____ selection.

Accepted Answer

A) natural 
B) intersexual 
C) intrasexual 
D) stabilizing 
A) natural 
B) intersexual 
C) intrasexual 
D) stabilizing

Question 10

In a population of Mendel's garden peas, the frequency of the dominant A (yellow flower) allele is 80%. Let p represent the frequency of the A allele and q represent the frequency of the a allele. Assuming that the population is in Hardy-Weinberg equilibrium, what are the genotype frequencies?

Accepted Answer

A) 64% AA, 32% Aa, 4% aa 
B) 50% AA, 25% Aa, 25% aa 
C) 16% AA, 40% Aa, 44% aa 
D) 75% AA, 15% Aa, 10% aa 
E) 80% AA, 10% Aa, 10% aa 
A) 64% AA, 32% Aa, 4% aa 
B) 50% AA, 25% Aa, 25% aa 
C) 16% AA, 40% Aa, 44% aa 
D) 75% AA, 15% Aa, 10% aa 
E) 80% AA, 10% Aa, 10% aa

Question 11

Which type of selection DECREASES overall variability in the specific trait?

Accepted Answer

A) directional selection 
B) disruptive selection 
C) natural selection 
D) stabilizing selection 
A) directional selection 
B) disruptive selection 
C) natural selection 
D) stabilizing selection

Question 12

The figure below shows the results of a series of observations and experiments on tail length in male African widowbirds. The black bars represent manipulated tail lengths by researchers (they actually added length to the tail feathers of the experimental birds). From the black bars on the figure, we see clearly that the male birds that have been artificially manipulated to have super-long tails are very good at attracting mates, approximated by the number of active nests for each male. Why then are the male tails we see in nature (open bars on the figure) so much shorter?

Accepted Answer

Because natural selection intervenes. Bi

Question 13

Genetic variation in a population refers to which of the following?

Accepted Answer

A) multiple individuals breeding together 
B) multiple alleles within a gene pool 
C) multiple phenotypes with the same genotype 
D) multiple genes within a genome 
E) multiple offspring with advantageous mutations 
A) multiple individuals breeding together 
B) multiple alleles within a gene pool 
C) multiple phenotypes with the same genotype 
D) multiple genes within a genome 
E) multiple offspring with advantageous mutations

Question 14

If two populations are thought to be diverging from one another, what would you expect to observe?

Accepted Answer

A) an accumulation of different mutations in different populations 
B) the same genotypes, but different phenotypes 
C) more shared mutations in different populations 
D) an increase in similarity of alleles coding for proteins 
A) an accumulation of different mutations in different populations 
B) the same genotypes, but different phenotypes 
C) more shared mutations in different populations 
D) an increase in similarity of alleles coding for proteins

Question 15

Why is it thought that the majority of natural selection is stabilizing selection?

Accepted Answer

A) Most mutations are deleterious and produce an extreme phenotype that is selected against. 
B) Most mutations are beneficial and produce intermediate phenotypes. 
C) Mutations produce extreme phenotypes, which are selected for. 
D) Artificial selection is the most common, which is a type of stabilizing selection. 
E) Directional selection is more common because it increases adaptations to the environment. 
A) Most mutations are deleterious and produce an extreme phenotype that is selected against. 
B) Most mutations are beneficial and produce intermediate phenotypes. 
C) Mutations produce extreme phenotypes, which are selected for. 
D) Artificial selection is the most common, which is a type of stabilizing selection. 
E) Directional selection is more common because it increases adaptations to the environment.

Question 16

What is the result of a mutation that occurs in somatic cells?

Accepted Answer

A) The mutation will be passed along to the organism's offspring. 
B) The mutation may be expressed in the individual, but will not be passed along to its offspring. 
C) The mutation will be deleterious. 
D) There will never be any visible effect. 
E) The mutation will prevent all reproduction. 
A) The mutation will be passed along to the organism's offspring. 
B) The mutation may be expressed in the individual, but will not be passed along to its offspring. 
C) The mutation will be deleterious. 
D) There will never be any visible effect. 
E) The mutation will prevent all reproduction.

Question 17

Male northern elephant seals (Mirounga angustirostris) compete with one another for territories along the beach. Males defend these territories throughout the breeding season. The males that win the male-male competitions defend the "best" territories, and have access to females that stay in that territory of the beach. The females land on the beach during mating season, choosing which territory of the beach to join. They then disproportionately breed with the male that defends that area of the beach. At what point may intersexual selection occur in these elephant seals?

Accepted Answer

A) when the female is swimming to the beach 
B) when the female lands on the beach and chooses her resting location 
C) when the male defends his group of females against a different male 
D) when the male mates with a female within his group 
E) when the female leaves the beach after mating with a male 
A) when the female is swimming to the beach 
B) when the female lands on the beach and chooses her resting location 
C) when the male defends his group of females against a different male 
D) when the male mates with a female within his group 
E) when the female leaves the beach after mating with a male

Question 18

Which of the following research questions would a population geneticist be MOST likely to ask?

Accepted Answer

A) How much genetic variability is found in sperm whales? 
B) How can we explain the amount of genetic diversity in Adelie penguins? 
C) Why do some species have more genetic diversity than others? 
D) All of these choices are correct. 
A) How much genetic variability is found in sperm whales? 
B) How can we explain the amount of genetic diversity in Adelie penguins? 
C) Why do some species have more genetic diversity than others? 
D) All of these choices are correct.

Question 19

Small populations of a diminutive rodent, each with 100 individuals, live on two small neighboring islands, Rack and Oon. The Rack population is fixed for the A allele at the Agility gene; the Oon population is fixed for the a allele at the Agility gene. Ten individuals from Rack get carried on a drifting fallen tree trunk to Oon. Assuming the drifting individuals arrived at the start of the breeding season and that the rodents breed every year and die once they've raised their offspring, what are the genotype frequencies in the Oon population the year after the accidental migration event?

Accepted Answer

A) AA 0.0; Aa 0.0; aa 1.0 
B) AA (1/11)2; Aa 2(1/11)(10/11); aa (10/11)2 
C) AA (10/11)2; Aa 2(1/11)(10/11); aa (1/11)2 
D) AA 1.0; Aa 0.0; aa 1.0 
E) The genotype frequencies cannot be determined from the information provided. 
A) AA 0.0; Aa 0.0; aa 1.0 
B) AA (1/11)2; Aa 2(1/11)(10/11); aa (10/11)2 
C) AA (10/11)2; Aa 2(1/11)(10/11); aa (1/11)2 
D) AA 1.0; Aa 0.0; aa 1.0 
E) The genotype frequencies cannot be determined from the information provided.

Question 20

Which of the following is an example of stabilizing selection?

Accepted Answer

A) selection for average birth weight in humans 
B) antibiotic resistance in bacteria 
C) decrease in the number of birds with intermediate-sized beaks who are unable to eat large or small seeds 
D) breeding dogs from wolves 
A) selection for average birth weight in humans 
B) antibiotic resistance in bacteria 
C) decrease in the number of birds with intermediate-sized beaks who are unable to eat large or small seeds 
D) breeding dogs from wolves

Exam 21: Evolution: How Genotypes and Phenotypes Change Over Time

Ronald Fisher developed a critical idea for the modern synthesis of Darwin and Mendel. What is the basis of this synthesis?

Hardy-Weinberg can predict genotype frequencies from _____ frequencies.

Which of the following statements is TRUE regarding the tail of a male peacock?

Both Charles Darwin and Alfred Russel Wallace acknowledged the influence of the economist Thomas Malthus in the development of their ideas about natural selection. Specifically, Malthus's ideas about geometric population growth implied that:

In a population of Mendel's garden peas, the frequency of green-flowered plants (genotype aa) is 49%. The population is in Hardy-Weinberg equilibrium. What are the frequencies of the AA and Aa genotypes?

Which of the following is NOT a condition of the Hardy-Weinberg equilibrium?

From an evolutionary perspective, germ-line mutations are more significant than somatic mutations. This is because:

Hammer-head bats are a species of African fruit bat. During the breeding season, males gather in mating arenas, where they display to females who pass through and assess males before selecting individuals with which to mate. This is an example of _____ selection.

In a population of Mendel's garden peas, the frequency of the dominant A (yellow flower) allele is 80%. Let p represent the frequency of the A allele and q represent the frequency of the a allele. Assuming that the population is in Hardy-Weinberg equilibrium, what are the genotype frequencies?

Which type of selection DECREASES overall variability in the specific trait?

Genetic variation in a population refers to which of the following?

If two populations are thought to be diverging from one another, what would you expect to observe?

Why is it thought that the majority of natural selection is stabilizing selection?

What is the result of a mutation that occurs in somatic cells?

Which of the following research questions would a population geneticist be MOST likely to ask?

Which of the following is an example of stabilizing selection?

Life: Chemical, Cellular, and Evolutionary Foundations

The Molecules of Life

Nucleic Acids and Transcription

Translation and Protein Structure

Organizing Principles: Lipids, Membranes, and Cell Compartments

Making Life Work: Capturing and Using Energy

Cellular Respiration: Harvesting Energy From Carbohydrates and Other Fuel Molecules

Photosynthesis: Using Sunlight to Build Carbohydrates

Cell Signaling

Cell and Tissue Architecture: Cytoskeleton, Cell Junctions, and Extracellular Matrix

Cell Division: Variations, Regulation, and Cancer

Dna Replication and Manipulation

Genomes

Mutation and Dna Repair

Genetic Variation

Mendelian Inheritance

Inheritance of Sex Chromosomes, Linked Genes, and Organelles

The Genetic and Environmental Basis of Complex Traits

Genetic and Epigenetic Regulation

Genes and Development

Species and Speciation

Evolutionary Patterns: Phylogeny and Fossils

Human Origins and Evolution

Cycling Carbon

Bacteria and Archaea

Eukaryotic Cells: Origins and Diversity

Being Multicellular

Plant Structure and Function: Moving Photosynthesis Onto Land

Plant Reproduction: Finding Mates and Dispersing Young

Plant Growth and Development

Plant Defense: Keeping the World Green

Plant Diversity

Fungi: Structure, Function, and Diversity

Animal Nervous Systems

Animal Sensory Systems and Brain Function

Animal Movement: Muscles and Skeletons

Animal Endocrine Systems

Animal Cardiovascular and Respiratory Systems

Animal Metabolism, Nutrition, and Digestion

Animal Renal Systems: Water and Waste

Animal Reproduction and Development

Animal Immune Systems

Animal Diversity

Animal Behavior

Population Ecology

Species Interactions, Communities, and Ecosystems

Biomes and Global Ecology

The Anthropocene: Humans As a Planetary Force

Filters