Deck 21: Microevolution: Genetic Changes Within Populations

Question 1

In humans, a diploid organism, an individual's genotype includes ____ of each autosomal gene.

A) one copy
B) two copies
C) hundreds of copies
D) thousands of copies
E) millions of copies

Answer 1

B

Question 2

The existence of discrete variants of a particular character is known as ____.

A) homozygous dominance
B) a quantitative trait
C) genotypic variation
D) a polymorphism
E) genetic equilibrium

Answer 2

D

Question 3

Mendel inferred the genetic basis of ____, such as flower color in peas, by crossing plants with different phenotypes.

A) adaptive traits
B) allele shuffling
C) allelic recombination
D) quantitative traits
E) qualitative traits

Answer 3

E

Question 4

The sum of all gene copies at all gene loci in all individuals in a population defines a ____.

A) ploidy level
B) genome
C) polymorphism
D) gene pool
E) genetic database

Question 5

The Hardy-Weinberg principle specifies the conditions under which a population of diploid organisms achieves ____.

A) progressive evolution
B) allopatric speciation
C) adaptive radiation
D) punctuated equilibrium
E) genetic equilibrium

Question 6

The gene locus governing flower color in snapdragons exhibits ____ because heterozygous individuals appear pink while homozygous individuals are either white or red.

A) codominance
B) equilibrium
C) autosomal dominance
D) complete dominance
E) incomplete dominance

Question 7

For an autosomal gene locus, there are ____ possible genotypes and ____ possible alleles.

A) two; three
B) two; four
C) three; two
D) three; four
E) four; three

Question 8

What is the most accurate definition of microevolution?

A) heritable changes in the genetics of a population
B) natural selection leading to adaptation
C) the occurrence of a series of mutations over time
D) the origin of new species through natural selection
E) the origin of major new forms of life over time

Question 9

Bacterial resistance to penicillin began to appear ____.

A) several decades after its first use
B) 100 years after its first use
C) after the drug was developed from synthetic sources
D) during the AIDS outbreak in the 1980s
E) within a few years of its introduction into general use

Question 10

A group of individuals of a single species that live together in the same place and time is referred to as a(n) ____.

A) community
B) biome
C) population
D) gene pool
E) ecosystem

Question 11

The Hardy-Weinberg formula is used to calculate changes in ____.

A) population size
B) speciation
C) allele frequencies
D) mutation
E) dimorphism

Question 12

The development of penicillin-resistant bacteria represents an example of ____.

A) punctuated equilibrium
B) speciation
C) genetic drift
D) microevolution
E) mutation

Question 13

Most new alleles probably arise from ____.

A) crossing over between homologous chromosomes
B) independent assortment of nonhomologous chromosomes
C) rearrangement of existing alleles into new combinations
D) small-scale mutations in DNA
E) large-scale changes in chromosome structure

Question 14

In the 1960s, evolutionary biologists identified protein polymorphisms using ____, which allowed them to infer how much genetic variation exists within populations.

A) genome sequencing
B) gel electrophoresis
C) artificial selection
D) polymerase chain reactions
E) DNA microarrays

Question 15

In an isolated population of fruit flies, 4% of the individuals have pink eyes, a homozygous recessive condition, and 96% have the dominant black eye phenotype. What percentage of the population are heterozygotes?

A) 32%
B) 16%
C) 48%
D) 88%
E) 4%

Question 16

Characters that exist in two or more discrete states are described as exhibiting ____.

A) quantitative variation
B) qualitative variation
C) genetic equilibrium
D) punctuated equilibrium
E) disruptive selection

Question 17

John G. Swallow and his colleagues used ____ techniques to demonstrate that the observed differences in activity levels of house mice have a genetic basis.

A) artificial selection
B) sexual selection
C) random mating
D) gel electrophoresis
E) DNA sequencing

Question 18

According to the Hardy-Weinberg principle, microevolution occurs when ____.

A) a population experiences a shift in allele frequencies
B) no mutations are occurring in a population
C) a population is closed to migration from other populations
D) a feature of an individual animal changes through use or disuse
E) when a population has different forms of the same gene

Question 19

In some studies that use observational rather than experimental data, investigators develop ____, which conceptually predict what they would see if a particular factor had no effect.

A) control treatments
B) null models
C) experimental controls
D) null treatments
E) experimental models

Question 20

Researchers study the inheritance of particular human traits by ____.

A) performing breeding experiments
B) crossing individuals with different phenotypes
C) analyzing genealogical pedigrees
D) selectively breeding certain individuals
E) using artificial selection techniques

Question 21

The agent of microevolutionary change that is most likely to introduce genetic variation from another population is referred to as ____.

A) genetic drift
B) gene flow
C) natural selection
D) mutation
E) nonrandom mating

Question 22

Microevolution is ____.

A) the appearance of a life form adapted to a new adaptive zone
B) the formation of a new species
C) the occurrence of a new mutation
D) a change in allele frequencies within a population
E) the gradual change in the form of fossils over geological time

Question 23

With ____ selection, the frequency of the mean phenotype decreases while the frequencies of extreme phenotypes increase.

A) directional
B) stabilizing
C) disruptive
D) sexual
E) dominant

Question 24

The high incidence of Ellis-van Creveld syndrome among the Old Order Amish population is caused by ____.

A) a population bottleneck
B) artificial selection
C) sexual selection
D) inbreeding
E) random mating

Question 25

On occasion, a stressful factor such as disease, starvation, or drought kills a large proportion of the individuals in a population, producing ____ that dramatically reduces the population size.

A) natural selection
B) artificial selection
C) a lethal mutation
D) a founder effect
E) a population bottleneck

Question 26

Natural selection that shifts the adaptation of an entire population toward one extreme is known as ____.

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

Question 27

The phenomenon of chance events causing the allele frequencies in a population to change unpredictably is known as ____.

A) genetic drift
B) gene flow
C) deleterious mutations
D) nonrandom mating
E) natural selection

Question 28

The only survivors of a colony on Venus are a man and a woman, who both happen to originally be from southern Ukraine. Their descendants will show the effect of ____.

A) genetic drift
B) punctuated equilibrium
C) excessive mutation
D) heterozygote advantage
E) frequency-dependent selection

Question 29

Dispersal agents, such as pollen-carrying wind or seed-carrying animals, are responsible for ____ in most plant populations because they often introduce novel alleles into a population.

A) gene flow
B) genetic drift
C) mutations
D) nonrandom mating
E) natural selection

Question 30

Microevolutionary change resulting from the differential survivorship or reproduction of individuals with different genotypes is known as ____.

A) nonrandom mating
B) mutation
C) gene flow
D) natural selection
E) genetic drift

Question 31

Natural selection acts upon the ____ to create microevolutionary change.

A) alleles in the gene pool of a population
B) genotypic frequencies of a population
C) alleles of an individual organism
D) allele frequencies in a population
E) phenotype of an individual organism

Question 32

The source of new alleles within a population is ____.

A) natural selection
B) mutation
C) nonrandom mating
D) adaptation
E) genetic drift

Question 33

If there are two alleles for a gene in a population, and the frequency of the dominant allele (p) is .5, then the frequency of the recessive allele (q) is ____.

A) )5
B) )025
C) )25
D) )75
E) )05

Question 34

Which circumstance violates the conditions of the Hardy-Weinberg model?

A) The population is infinitely large.
B) The population is closed to migration from other populations.
C) No mutations are occurring.
D) All genotypes in the population survive and reproduce equally well.
E) Nonrandom mating with respect to genotypes occurs between individuals.

Question 35

Dog breeders produced the long body and short legs of a dachshund by employing ____ selection.

A) dominant
B) directional
C) stabilizing
D) disruptive
E) sexual

Question 36

The process by which successful traits become more common in subsequent generations is called ____.

A) speciation
B) mutation
C) natural selection
D) genetic drift
E) gene flow

Question 37

In humans, ____ mutations cause forms of Ehlers-Danlos syndrome, a disruption of collagen synthesis that may result in loose skin or weak joints.

A) frameshift
B) deleterious
C) advantageous
D) lethal
E) neutral

Question 38

Directional selection favors ____.

A) intermediate phenotypes
B) phenotypes at one end of the distribution
C) phenotypic extremes at both ends
D) heterozygous individuals
E) homozygous individuals

Question 39

If a lethal mutation occurs in a dominant allele, ____ individuals will die from its effects.

A) only homozygous dominant
B) only heterozygous
C) only homozygous recessive
D) both homozygous dominant and heterozygous
E) both homozygous dominant and homozygous recessive

Question 40

The contribution an individual makes to the gene pool of the next generation compared to the contributions of other individuals is called ____.

A) competition
B) genetic drift
C) relative fitness
D) gene flow
E) mutation

Question 41

Changing environmental conditions would most likely cause an existing species to undergo ____.

A) disruptive selection
B) deleterious mutation
C) directional selection
D) stabilizing selection
E) lethal mutation

Question 42

The success of camouflage from predatory birds drives the predominant phenotypes in snail color. This is an example of ____.

A) predation as an agent of natural selection
B) sexual selection
C) predation as an agent of artificial selection
D) the founder effect
E) a selectively neutral phenotype

Question 43

Individuals with one sickle cell allele and one normal hemoglobin allele are not affected by the malaria parasite because of ____.

A) neutral mutations
B) heterozygote advantage
C) frequency-dependent selection
D) disruptive selection
E) stabilizing selection

Question 44

Genetic drift is most likely to lead to ____.

A) artificial selection
B) mutation
C) the founder effect
D) gene flow
E) adaptation

Question 45

Inbreeding is primarily due to ____.

A) gene flow
B) nonrandom mating
C) neutral mutations
D) natural selection
E) adaptive radiation

Question 46

Genetic drift will have a progressively larger impact on allele frequencies in a population as ____.

A) gene flow increases
B) population size decreases
C) mutation rate decreases
D) population size increases
E) random mating increases

Question 47

Research by Malte Andersson suggests the long tail feathers of male African widowbirds are a product of ____ selection because females are more strongly attracted to males with long tails than to males with short tails.

A) disruptive
B) intersexual
C) intrasexual
D) artificial
E) stabilizing

Question 48

Sometimes the most abundant color form of an animal is preyed upon more extensively than less common forms. This illustrates the phenomenon of ____ selection.

A) stabilizing
B) directional
C) disruptive
D) frequency-dependent
E) artificial

Question 49

When a few individuals colonize a distant locality and start a new population, the allele frequencies of the gene pool may be different than those in the original population. This is known as ____.

A) the founder effect
B) a population bottleneck
C) genetic equilibrium
D) the Hardy-Weinberg principle
E) natural selection

Question 50

When male moose engage in their annual battles, butting heads with their oversized antlers, they are exhibiting ____ selection.

A) stabilizing
B) disruptive
C) directional
D) intrasexual
E) intersexual

Question 51

Natural selection exerts little or no effect on traits that appear during an individual's ____.

A) preadolescent years
B) embryonic development
C) juvenile phase
D) postreproductive life
E) reproductive life

Question 52

Natural selection results most directly in ____.

A) adaptation
B) mutations
C) new species
D) genetic drift
E) gene flow

Question 53

With frequency-dependent selection, highest mortality can be expected in ____.

A) the most abundant genotype
B) the least abundant genotype
C) the least well-adapted genotype
D) heterozygous genotypes
E) homozygous recessive genotypes

Question 54

Andrew P. Hendry and colleagues discovered that Galápagos ground finches with small bills and ground finches with large bills were more common and had higher fitness than birds with bills of intermediate size, a demonstration of ____ selection.

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

Question 55

Snow geese usually select mates of their own color, an example of ____.

A) genetic drift
B) founder effects
C) population bottlenecks
D) nonrandom mating
E) random mating

Question 56

The stable presence of two or more phenotypes in a population is called a ____.

A) balanced polymorphism
B) mixed gene pool
C) mutation pressure
D) population bottleneck
E) competitive advantage

Question 57

Genetic variations that confer no apparent selective advantage or disadvantage in a particular environment are said to be selectively ____.

A) random
B) deleterious
C) neutral
D) benign
E) stabilizing

Question 58

In many species, sexual selection is the most probable cause of ____, differences in the size or appearance of males and females.

A) adaptive radiation
B) inbreeding
C) mutation
D) polymorphism
E) sexual dimorphism

Question 59

Very small and very large human newborns are less likely to survive than those born at an intermediate weight due to ____.

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

Question 60

Disadvantageous recessive alleles are protected from natural selection due to ____.

A) homozygosity
B) diploidy
C) genetic drift
D) haploidy
E) adaptation

Question 61

A scientist could test how the traits of desert plants are adaptive by ____.

A) transplanting individuals that have the trait into moister habitats
B) selectively breeding individuals displaying that trait
C) conducting straightforward experiments in the desert habitat
D) crossing individuals in the desert with individuals in moister habitats
E) comparing them to traits in related species from moister habitats

Question 64

Hybridization between different species is rare because it ____.

A) requires the breakdown of a barrier preventing interbreeding
B) causes lethal mutations in hybrid offspring
C) leads to the exchange of genes between closely related species
D) leads to gene flow between species
E) contradicts the species concept

Question 65

As adults, female ground finches on the Galápagos island of Daphne Major choose their mates according to characteristics they learned as young birds, a process known as ____.

A) sexual equilibrium
B) the founder effect
C) selective inbreeding
D) sexual imprinting
E) adaptive radiation

Question 66

The accumulation of traits that increase the relative fitness of organisms in their environment over time results in ____.

A) mutation
B) adaptation
C) heterozygote advantage
D) homozygote advantage
E) diploidy

Question 68

Any product of natural selection that increases the relative fitness of an organism in its environment is called a(n) ____.

A) neutral mutation
B) adaptive trait
C) founder effect
D) speciation event
E) polymorphic trait

Question 69

The Hardy-Weinberg principle describes how genotype frequencies are established in sexually reproducing organisms.

Question 70

Seeds of many plants fall to the ground when they mature. This is an example of a characteristic that is influenced by ____.

A) basic physical laws
B) adaptive evolution
C) chance events
D) genetic drift
E) neutral mutations

Question 71

Natural selection results in organisms perfectly adapted to their environments.

Question 72

Genetic variation can originate both from the production of new alleles and from the arrangement of existing alleles.

Question 73

Genetic drift is nonselective and therefore does not contribute to microevolution.

Question 74

Which of the following evolution-related events is in the correct cause-and-effect sequence?

A) mutation → variation → natural selection → adaptation → speciation
B) variation → adaptation → mutation → natural selection → speciation
C) speciation → adaptation → variation → mutation → natural selection
D) mutation → speciation →adaptation → variation → natural selection
E) natural selection → variation → mutation → adaptation → speciation

Question 75

Distinguish between quantitative and qualitative variation.

Question 76

Most copies of rare recessive alleles exist in ____.

A) homozygotes
B) heterozygotes
C) females
D) males
E) males and females equally

Question 77

How can a researcher determine whether variation in a phenotypic trait is caused by environmental factors or by genetic differences?

Question 78

How can harmful alleles persist in a population despite natural selection?

Question 79

The fossil record reveals that the structure of shoulder joints in birds, which is essential for flight, is an adaptation that originated in ____.

A) nonflying birds
B) ancient bats
C) ancestral birds
D) nonflying dinosaurs
E) flying dinosaurs

Question 80

The bipedal posture of humans evolved from ____.

A) deleterious mutations
B) a novel mutation
C) quadrupedal ancestors
D) bipedal ancestors
E) flightless birds