Question 1

Over the course of evolutionary time, what should occur?

Accepted Answer

A) Methylated DNA should become fixed in the gene pools of bacterial species. 
B) Nonmethylated DNA should become fixed in the gene pools of bacteriophages. 
C) Methylated DNA should become fixed in the gene pools of bacteriophages. 
D) Methylated and nonmethylated strains should be maintained among both bacteria and bacteriophages, with ratios that vary over time. 
E) Both A and B are correct. 
A) Methylated DNA should become fixed in the gene pools of bacterial species. 
B) Nonmethylated DNA should become fixed in the gene pools of bacteriophages. 
C) Methylated DNA should become fixed in the gene pools of bacteriophages. 
D) Methylated and nonmethylated strains should be maintained among both bacteria and bacteriophages, with ratios that vary over time. 
E) Both A and B are correct.

Question 2

Natural selection changes allele frequencies in populations because some __________ survive and reproduce more successfully than others.

Accepted Answer

A) alleles 
B) loci 
C) gene pools 
D) species 
E) individuals 
A) alleles 
B) loci 
C) gene pools 
D) species 
E) individuals

Question 3

Fossil evidence indicates that horses have gradually increased in size over geologic time. Which of the following terms best describes this?

Accepted Answer

A) artificial selection 
B) directional selection 
C) stabilizing selection 
D) disruptive selection 
E) sexual selection 
A) artificial selection 
B) directional selection 
C) stabilizing selection 
D) disruptive selection 
E) sexual selection

Question 4

The higher the proportion of loci that are "fixed" in a population, the lower is that population's

Accepted Answer

A) nucleotide variability. 
B) genetic polyploidy. 
C) average heterozygosity. 
D) A, B, and C 
E) A and C only 
A) nucleotide variability. 
B) genetic polyploidy. 
C) average heterozygosity. 
D) A, B, and C 
E) A and C only

Exam 23: The Evolution of Populations

Over the course of evolutionary time, what should occur?

Natural selection changes allele frequencies in populations because some __________ survive and reproduce more successfully than others.

Fossil evidence indicates that horses have gradually increased in size over geologic time. Which of the following terms best describes this?

The higher the proportion of loci that are "fixed" in a population, the lower is that population's

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and the Fitness of the Environment

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration: Harvesting Chemical Energy

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Control of Gene Expression

Viruses

Biotechnology

Genomes and Their Evolution

Descent With Modification: a Darwinian View of Life

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity Ii: the Evolution of Seed Plants

Fungi

An Introduction to Animal Diversity

Invertebrates

Vertebrates

Plant Structure, Growth, and Development

Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems

Conservation Biology and Restoration Ecology

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