Question 1

A defining characteristic of allopatric speciation is

Accepted Answer

A) the appearance of new species in the midst of old ones. 
B) asexually reproducing populations. 
C) geographic isolation. 
D) artificial selection. 
E) large populations. 
A) the appearance of new species in the midst of old ones. 
B) asexually reproducing populations. 
C) geographic isolation. 
D) artificial selection. 
E) large populations. C

Question 2

The following questions refer to the paragraph and graphs below.
In a hypothetical situation, the National Park Service, which administers Grand Canyon National Park in Arizona, builds a footbridge over the Colorado River at the bottom of the canyon. The footbridge permits interspersal of two closely related antelope squirrels. Previously, one type of squirrel had been restricted to the terrain south of the river, and the other type had been restricted to terrain on the north side of the river. Immediately before and ten years after the bridge's completion, ten antelope squirrels from both sides of the river were collected, blood samples were taken, and frequencies of alleles unique to the two types of antelope squirrels were determined (see graphs below).

-Upon undergoing change, which of these genes is most likely to result in speciation while a geographic barrier separates two populations of a flowering-plant species?

Accepted Answer

A) one that affects the rate of chlorophyll a synthesis 
B) one that affects the amount of growth hormone synthesized per unit time 
C) one that affects the compatibility of male pollen and female reproductive parts 
D) one that affects the average depth to which roots grow down through the soil 
E) one that affects how flexible the stems are 
A) one that affects the rate of chlorophyll a synthesis 
B) one that affects the amount of growth hormone synthesized per unit time 
C) one that affects the compatibility of male pollen and female reproductive parts 
D) one that affects the average depth to which roots grow down through the soil 
E) one that affects how flexible the stems are C

Question 3

Which of the following statements about species, as defined by the biological species concept, is (are)correct?
I. Biological species are defined by reproductive isolation.
II. Biological species are the model used for grouping extinct forms of life.
III. The biological species is the largest unit of population in which successful reproduction is possible.

Accepted Answer

A) I only 
B) II only 
C) I and III 
D) II and III 
E) I, II, and III 
A) I only 
B) II only 
C) I and III 
D) II and III 
E) I, II, and III C

Question 4

The questions below are based on the following description.
Several closely related frog species of the genus Rana are found in the forests of the southeastern United States. The species boundaries are maintained by reproductive barriers. In each case, match the various descriptions of frogs below with the appropriate reproductive barrier listed.
-One species lives only in tree holes; another species lives only in streams.

Accepted Answer

A) behavioral 
B) gametic 
C) habitat 
D) temporal 
E) mechanical 
A) behavioral 
B) gametic 
C) habitat 
D) temporal 
E) mechanical

Question 5

The questions below are based on the following description.
Several closely related frog species of the genus Rana are found in the forests of the southeastern United States. The species boundaries are maintained by reproductive barriers. In each case, match the various descriptions of frogs below with the appropriate reproductive barrier listed.
-One species mates at the season when daylight is increasing from 13 hours to 13 hours, 15 minutes; another species mates at the season when daylight is increasing from 14 hours to 14 hours, 15 minutes.

Accepted Answer

A) behavioral 
B) gametic 
C) habitat 
D) temporal 
E) mechanical 
A) behavioral 
B) gametic 
C) habitat 
D) temporal 
E) mechanical

Question 6

You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use?

Accepted Answer

A) biological 
B) phylogenetic 
C) ecological 
D) morphological 
A) biological 
B) phylogenetic 
C) ecological 
D) morphological

Question 7

The following questions refer to the paragraph and graphs below.
In a hypothetical situation, the National Park Service, which administers Grand Canyon National Park in Arizona, builds a footbridge over the Colorado River at the bottom of the canyon. The footbridge permits interspersal of two closely related antelope squirrels. Previously, one type of squirrel had been restricted to the terrain south of the river, and the other type had been restricted to terrain on the north side of the river. Immediately before and ten years after the bridge's completion, ten antelope squirrels from both sides of the river were collected, blood samples were taken, and frequencies of alleles unique to the two types of antelope squirrels were determined (see graphs below).

-The data in the graphs above indicate that

Accepted Answer

A) a hybrid zone was established after the completion of the bridge. 
B) no interspersal of the two types of squirrel occurred after the completion of the bridge. 
C) gene flow occurred from one type of squirrel into the gene pool of the other type of squirrel. 
D) 2-way migration of squirrels occurred across the bridge, but without hybridization. 
E) some northern squirrels migrated south, but no southern squirrels migrated north across the bridge. 
A) a hybrid zone was established after the completion of the bridge. 
B) no interspersal of the two types of squirrel occurred after the completion of the bridge. 
C) gene flow occurred from one type of squirrel into the gene pool of the other type of squirrel. 
D) 2-way migration of squirrels occurred across the bridge, but without hybridization. 
E) some northern squirrels migrated south, but no southern squirrels migrated north across the bridge.

Question 8

Which of the following factors would not contribute to allopatric speciation?

Accepted Answer

A) A population becomes geographically isolated from the parent population. 
B) The separated population is small, and genetic drift occurs. 
C) The isolated population is exposed to different selection pressures than the ancestral population. 
D) Different mutations begin to distinguish the gene pools of the separated populations. 
E) Gene flow between the two populations is extensive. 
A) A population becomes geographically isolated from the parent population. 
B) The separated population is small, and genetic drift occurs. 
C) The isolated population is exposed to different selection pressures than the ancestral population. 
D) Different mutations begin to distinguish the gene pools of the separated populations. 
E) Gene flow between the two populations is extensive.

Question 9

According to the punctuated equilibria model,

Accepted Answer

A) natural selection is unimportant as a mechanism of evolution. 
B) given enough time, most existing species will branch gradually into new species. 
C) most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species. 
D) most evolution occurs in sympatric populations. 
E) speciation is usually due to a single mutation. 
A) natural selection is unimportant as a mechanism of evolution. 
B) given enough time, most existing species will branch gradually into new species. 
C) most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species. 
D) most evolution occurs in sympatric populations. 
E) speciation is usually due to a single mutation.

Question 10

The questions below are based on the following description.
Several closely related frog species of the genus Rana are found in the forests of the southeastern United States. The species boundaries are maintained by reproductive barriers. In each case, match the various descriptions of frogs below with the appropriate reproductive barrier listed.
-Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms?

Accepted Answer

A) reduced hybrid fertility 
B) hybrid breakdown 
C) mechanical isolation 
D) habitat isolation 
E) gametic isolation 
A) reduced hybrid fertility 
B) hybrid breakdown 
C) mechanical isolation 
D) habitat isolation 
E) gametic isolation

Question 11

There is still some controversy among biologists about whether Neanderthals should be placed within the same species as modern humans, or into a separate species of their own. Most DNA sequence data analyzed so far indicate that there was probably little or no gene flow between Neanderthals and Homo sapiens. Which species concept is most applicable in this example?

Accepted Answer

A) phylogenetic 
B) ecological 
C) morphological 
D) biological 
A) phylogenetic 
B) ecological 
C) morphological 
D) biological

Question 12

The most likely explanation for the recent decline in cichlid species diversity in Lake Victoria is

Accepted Answer

A) reinforcement. 
B) fusion. 
C) stability. 
D) geographic isolation. 
E) polyploidy. 
A) reinforcement. 
B) fusion. 
C) stability. 
D) geographic isolation. 
E) polyploidy.

Question 13

The following questions refer to the evolutionary tree below, whose horizontal axis represents time (present time is on the far right) and whose vertical axis represents morphological change.
   Figure 24.1
-Which conclusion can be drawn from this evolutionary tree?

Accepted Answer

A) Gradualistic speciation and speciation involving punctuated equilibrium are mutually exclusive concepts; only one of them can occur. 
B) Eldredge and Gould would deny that the lineages labeled X, Y, and Z could represent True species. 
C) Assuming that the tip of each line represents a species, there are five extant (i.e., not extinct)species resulting from the earliest common ancestor. 
D) A single clade (i.e., a group of species that share a common ancestor)can exhibit both gradualism and punctuated equilibrium. 
E) V and W shared a common ancestor more recently than any of the other species. 
A) Gradualistic speciation and speciation involving punctuated equilibrium are mutually exclusive concepts; only one of them can occur. 
B) Eldredge and Gould would deny that the lineages labeled X, Y, and Z could represent True species. 
C) Assuming that the tip of each line represents a species, there are five extant (i.e., not extinct)species resulting from the earliest common ancestor. 
D) A single clade (i.e., a group of species that share a common ancestor)can exhibit both gradualism and punctuated equilibrium. 
E) V and W shared a common ancestor more recently than any of the other species.

Question 14

What was the species concept most used by Linnaeus?

Accepted Answer

A) biological 
B) morphological 
C) ecological 
D) phylogenetic 
A) biological 
B) morphological 
C) ecological 
D) phylogenetic

Question 15

Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools?

Accepted Answer

A) phylogenetic 
B) ecological 
C) biological 
D) morphological 
A) phylogenetic 
B) ecological 
C) biological 
D) morphological

Question 16

Rank the following from most general to most specific: 1. gametic isolation
2) reproductive isolating mechanism
3) pollen-stigma incompatibility
4) prezygotic isolating mechanism

Accepted Answer

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

Question 17

A hybrid zone is properly defined as

Accepted Answer

A) an area where two closely related species' ranges overlap. 
B) an area where mating occurs between members of two closely related species, producing viable offspring. 
C) a zone that features a gradual change in species composition where two neighboring ecosystems border each other. 
D) a zone that includes the intermediate portion of a cline. 
E) an area where members of two closely related species intermingle, but experience no gene flow. 
A) an area where two closely related species' ranges overlap. 
B) an area where mating occurs between members of two closely related species, producing viable offspring. 
C) a zone that features a gradual change in species composition where two neighboring ecosystems border each other. 
D) a zone that includes the intermediate portion of a cline. 
E) an area where members of two closely related species intermingle, but experience no gene flow.

Question 18

The most likely explanation for the high rate of sympatric speciation that apparently existed among the cichlids of Lake Victoria in the past is

Accepted Answer

A) sexual selection. 
B) habitat differentiation. 
C) polyploidy. 
D) pollution. 
E) introduction of a new predator. 
A) sexual selection. 
B) habitat differentiation. 
C) polyploidy. 
D) pollution. 
E) introduction of a new predator.

Question 19

Among known plant species, which of these have been the two most commonly occurring phenomena leading to the origin of new species?
1) allopatric speciation
2) sympatric speciation
3) sexual selection
4) polyploidy

Accepted Answer

A) 1 and 3 
B) 1 and 4 
C) 2 and 3 
D) 2 and 4 
A) 1 and 3 
B) 1 and 4 
C) 2 and 3 
D) 2 and 4

Question 20

The origin of a new plant species by hybridization, coupled with accidents during nuclear division, is an example of

Accepted Answer

A) allopatric speciation. 
B) sympatric speciation. 
C) autopolyploidy. 
D) habitat selection. 
A) allopatric speciation. 
B) sympatric speciation. 
C) autopolyploidy. 
D) habitat selection.

Exam 24: The Origin of Species

A defining characteristic of allopatric speciation is

You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use?

Which of the following factors would not contribute to allopatric speciation?

According to the punctuated equilibria model,

The most likely explanation for the recent decline in cichlid species diversity in Lake Victoria is

The following questions refer to the evolutionary tree below, whose horizontal axis represents time (present time is on the far right) and whose vertical axis represents morphological change. Figure 24.1 -Which conclusion can be drawn from this evolutionary tree?

What was the species concept most used by Linnaeus?

Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools?

Rank the following from most general to most specific: 1. gametic isolation 2) reproductive isolating mechanism 3) pollen-stigma incompatibility 4) prezygotic isolating mechanism

A hybrid zone is properly defined as

The most likely explanation for the high rate of sympatric speciation that apparently existed among the cichlids of Lake Victoria in the past is

Among known plant species, which of these have been the two most commonly occurring phenomena leading to the origin of new species? 1) allopatric speciation 2) sympatric speciation 3) sexual selection 4) polyploidy

The origin of a new plant species by hybridization, coupled with accidents during nuclear division, is an example of

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 Evolution of Populations

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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