Question 1

How do the founder effect and the immigration aspect of gene flow differ for the cheetah (Acinonyx jubatus)?

Accepted Answer

A) Gene flow involves cheetahs moving into an area with an established cheetah population,whereas founder effect involves cheetahs colonizing an area where there is no established cheetah population (but where there might be populations of other species). 
B) Both gene flow and founder effect involve cheetahs moving into established populations of cheetahs. 
C) Gene flow involves cheetahs moving into an area with an established population of another species (e.g.,lions),whereas founder effect involves cheetahs moving into an area where there is an established cheetah population. 
D) Both gene flow and founder effect involve cheetahs moving into an area where there is no established cheetah population. 
A) Gene flow involves cheetahs moving into an area with an established cheetah population,whereas founder effect involves cheetahs colonizing an area where there is no established cheetah population (but where there might be populations of other species). 
B) Both gene flow and founder effect involve cheetahs moving into established populations of cheetahs. 
C) Gene flow involves cheetahs moving into an area with an established population of another species (e.g.,lions),whereas founder effect involves cheetahs moving into an area where there is an established cheetah population. 
D) Both gene flow and founder effect involve cheetahs moving into an area where there is no established cheetah population.

Question 2

In some jacana species,males take care of the eggs and young,and females compete for territories and males against one another.Female jacanas are significantly larger than males.Which of these statements would you predict to be true of this bird species? 1. Male jacana fitness is primarily limited by ability to take care of eggs and raise young.
2) Female jacana fitness is limited by the number of males with which a female mates.
3) Variation in reproductive success should be greater in male jacanas than in females.
4) Variation in reproductive success should be greater in female jacanas than in males.
5) Males and females have equal variation in reproductive success.

Accepted Answer

A) 1 and 3 
B) 2 and 4 
C) 1,2,and 3 
D) 1,2,and 4 
E) 5 
A) 1 and 3 
B) 2 and 4 
C) 1,2,and 3 
D) 1,2,and 4 
E) 5

Question 3

Three-spined stickleback fish (Gasterosteus aculeatus)show substantial heritable variation in gill-raker length.Fish caught in open water tend to have longer gill rakers and eat different foods than those caught in shallower water.Longer gill rakers appear to function better for capturing open-water prey,while shorter gill rakers function better for capturing shallow-water prey.Which of the following types of selection is most likely to be found in a large lake (open water in middle and shallow water around the sides)with a high density of these fish?

Accepted Answer

A) directional selection 
B) stabilizing selection 
C) disruptive selection 
D) sexual selection 
E) no selection 
A) directional selection 
B) stabilizing selection 
C) disruptive selection 
D) sexual selection 
E) no selection

Question 4

A beneficial point mutation occurs in a plant ovule,which is fertilized.The seed matures,falls to the ground,and starts to grow.Is the plant's population likely to show evolutionary change as a result of this mutation? Why or why not?

Accepted Answer

The plant's population is unlikely to sh

Question 5

Based on whether the population in Figure 25.1 is in Hardy-Weinberg equilibrium,the researchers had already noted that negligible mutation and migration existed in this milkweed population,and the toxin does not affect the butterflies that pollinate these plants.Which of the following would be a logical conclusion about this milkweed population?

Accepted Answer

A) Genetic drift and selection are negligible. 
B) There is either a heterozygote advantage or stabilizing selection. 
C) There is either directional selection or sexual selection. 
D) There is either disruptive selection or inbreeding. 
A) Genetic drift and selection are negligible. 
B) There is either a heterozygote advantage or stabilizing selection. 
C) There is either directional selection or sexual selection. 
D) There is either disruptive selection or inbreeding.

Question 6

Cystic fibrosis is a genetic disorder in homozygous recessives (ff)that typically causes death in the early 30s.Over time,we would expect the f allele frequency to ________ for this trait.

Accepted Answer

A) remain the same 
B) increase 
C) decrease 
D) fluctuate 
A) remain the same 
B) increase 
C) decrease 
D) fluctuate

Question 7

The frequency of theB₁ allele (for an autosomal gene)in a population that is in Hardy-Weinberg equilibrium is 0.2 and the frequency of the B₂ allele is 0.8.The phenotype of allele B₁ is dominant to that of B₂.If females make up exactly half of the population,what is the frequency of the B₁ allele in the female population alone?

Accepted Answer

A) 0)1 
B) 0)2 
C) 0)4 
D) 0)8 
A) 0)1 
B) 0)2 
C) 0)4 
D) 0)8

Question 8

In a small population of alpine foxes,you observe increased ear length over a 10-year period.Can you conclude that increase in ear length is advantageous in this population?

Accepted Answer

A) yes 
B) no 
A) yes 
B) no

Question 9

A population of 500 field mice exhibits black or grey coat colours in approximately equal proportions.An individual mouse has a mutation that results in a brown coat colour;this mutation is passed along to many of its 20 offspring,who also exhibit a brown phenotype.If frequency-dependent selection is operating,which of the following would be true?

Accepted Answer

A) Mice within the population would breed nonrandomly to avoid inbreeding depression. 
B) Mice with the brown phenotype would have a higher fitness relative to individuals with black or grey coat colour. 
C) Mice with the brown phenotype would have a lower relative fitness to individuals with black or grey coat colour. 
D) Mice with the brown phenotype would have higher relative fitness if they were heterozygous. 
E) There would be more heterozygous individuals in the population than expected according to HWE. F)It is impossible to determine unless the type of selection is known. 
A) Mice within the population would breed nonrandomly to avoid inbreeding depression. 
B) Mice with the brown phenotype would have a higher fitness relative to individuals with black or grey coat colour. 
C) Mice with the brown phenotype would have a lower relative fitness to individuals with black or grey coat colour. 
D) Mice with the brown phenotype would have higher relative fitness if they were heterozygous. 
E) There would be more heterozygous individuals in the population than expected according to HWE. F)It is impossible to determine unless the type of selection is known.

Question 10

Figure 25.1 Use the following information when answering the corresponding question(s).
Researchers studying a small milkweed population note that some plants produce a toxin and other plants do not. They identify the gene responsible for toxin production. The dominant allele (T)codes for an enzyme that makes the toxin, and the recessive allele (t)codes for a nonfunctional enzyme that cannot produce the toxin. Heterozygotes produce an intermediate amount of toxin. The genotypes of all individuals in the population are determined (see chart)and used to determine the actual allele frequencies in the population.
  
-Refer to Figure 25.1.Is this population in Hardy-Weinberg equilibrium?

Accepted Answer

A) yes 
B) No;there are more heterozygotes than expected. 
C) No;there are more homozygotes than expected. 
D) More information is needed to answer this question. 
A) yes 
B) No;there are more heterozygotes than expected. 
C) No;there are more homozygotes than expected. 
D) More information is needed to answer this question.

Exam 25: Evolutionary Processes

How do the founder effect and the immigration aspect of gene flow differ for the cheetah (Acinonyx jubatus)?

A beneficial point mutation occurs in a plant ovule,which is fertilized.The seed matures,falls to the ground,and starts to grow.Is the plant's population likely to show evolutionary change as a result of this mutation? Why or why not?

Cystic fibrosis is a genetic disorder in homozygous recessives (ff)that typically causes death in the early 30s.Over time,we would expect the f allele frequency to ________ for this trait.

In a small population of alpine foxes,you observe increased ear length over a 10-year period.Can you conclude that increase in ear length is advantageous in this population?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Lipids, membranes, and the First Cells

Inside the Cell

Cell-Cell Interactions

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, RNA Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

Analyzing and Engineering Genes

Genomics

Principles of Development

An Introduction to Animal Development

An Introduction to Plant Development

Evolution by Natural Selection

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, signals, and Responses

Plant Reproduction

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Electrical Signals in Animals

Animal Sensory Systems and Movement

Chemical Signals in Animals

Animal Reproduction

The Immune System in Animals

An Introduction to Ecology

Behavioural Ecology

Population Ecology

Community Ecology

Ecosystems

Biodiversity and Conservation Biology

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