Chapter 17 Biology Tucker 2022

What is a mode of natural selection that favors a phenotype at one end of a range of variation? A. Directional selection B. Stabilizing selection C. Disruptive selection

A. Directional selection

Which of these scenarios is an example of disruptive selection? A. A new, unique color form arises from a mutation in a population of butterflies. B. The dark and light color morphs of a butterfly population are maintained, and the intermediate gray morph has been eliminated from the population. C. Darker colored morphs in a butterfly population are more adaptive than lighter colored morphs, and lighter colored morphs are eliminated from the population. D. Intermediate gray morphs of a butterfly population are maintained, and the extreme dark and light color morphs have been eliminated.

B. The dark and light color morphs of a butterfly population are maintained, and the intermediate gray morph has been eliminated from the population.

A heritable change in the nucleotide sequence of an organism's gamete is an example of _____. A. fertilization B. a mutation that can be passed on C. segregation of chromosomes D. independent assortment

B. a mutation that can be passed on

Which of the following is a change in allele frequency due to chance alone? A. Founder effect B. Bottleneck C. Genetic drift D. Gene flow

C. Genetic drift

selection that favors phenotypes at one end of the spectrum of existing variation

directional selection

individual's ability to survive and reproduce

evolutionary fitness (also, Darwinian fitness)

HbS, HbS=

homozygote & could be lethal

HbA, HbA=

homozygote & normal

What is the selection pressure for the sickle cell trait?

malaria

changes in a population's gene pool due to mate choice or other forces that cause individuals to mate with certain phenotypes more than others

nonrandom mating

Which of the following can cause mutations? Select all that apply. A. X-rays B. Errors during DNA replication C. Exposure to certain chemical compounds D. UV damage

A. X-rays B. Errors during DNA replication C. Exposure to certain chemical compounds D. UV damage

Organisms are typically considered different species if they _____. A. can no longer interbreed in nature to produce fertile offspring B. share adaptations that increase their fitness C. are varied in appearance D. migrate from one area to another

A. can no longer interbreed in nature to produce fertile offspring

What can result when a small group of related individuals forms a new, isolated population? Select all that apply. A. Increased gene flow B. Inbreeding C. Founder effect D. Bottleneck E. Decreased likelihood of fixed alleles

B. Inbreeding C. Founder effect D. Bottleneck

Which of the following statements correctly indicates why a species might undergo adaptive radiation in its evolutionary history? A. The species' environment was very strongly selecting for specific traits, and any new traits died out. B. New barriers to reproduction arose, stopping gene flow and isolating populations from one another. C. The species' environment remained relatively unchanged, so it did not exert new selection pressures on the species.

B. New barriers to reproduction arose, stopping gene flow and isolating populations from one another.

Which of the following examples best demonstrates directional selection? A. African finches B. Peppered Moths C. Weaver birds D. All of the above

B. Peppered Moths

What is maintenance of two or more alleles for a trait at high frequency in a population as a result of natural selection against homozygotes?

Balanced polymorphism

What is adaptive radiation? A. The event when a species no longer has living members B. Large-scale evolutionary patterns and trends in speciation C. A lineage undergoes a burst of genetic divergences that gives rise to many species D. Changes in allele frequency that are always occurring in natural populations

C. A lineage undergoes a burst of genetic divergences that gives rise to many species

Within a diploid animal species, what are potential sources of variation in shared, heritable traits? Select all that apply. A. Mitotic division of somatic cells B. Genetic engineering of somatic cells C. Meiosis D. Mutations in the germ line E. Fertilization

C. Meiosis D. Mutations in the germ line E. Fertilization

What is a phylogeny? A. The process of making hypotheses about evolutionary relationships among clades B. A group whose members share one or more defining derived traits C. The evolutionary history of a species or a group of species

C. The evolutionary history of a species or a group of species

How many total alleles are in the population's gene pool at timepoint B? A. 2 B. 40 C. 10 D. 20

D. 20

Normal hemoglobin allele

HbA

Mutated hemoglobin allele

HbS

Serious and can be fatal; causes high fevers, shaking chills, and flu-like; caused by plasmodium; vector/organism= mosquito

Malaria

What acts to promote traits and behaviors that increase an organism's chances of survival and reproduction, while eliminating those traits and behaviors that are to the organism's detriment.

Natural selection

What is one of the most dominant evolutionary forces?

Natural selection

The organisms that are better suited to their environment survive the pressure of selection agents

Selection Pressure

If an athlete works out in the gym every day, building up muscle strength, the athlete's offspring will not necessarily grow up to be a body builder. T/F

True

The case of the peppered moths is an example of ? a. Directional selection b. Disruptive selection c. Moth selection d. Stabilizing selection

a. Directional selection

Population genetics is the study of: a. how selective forces change the allele frequencies in a population over time b. the genetic basis of population-wide traits c. whether traits have a genetic basis d. the degree of inbreeding in a population

a. how selective forces change the allele frequencies in a population over time

When males and females of a population look or act differently, it is referred to as ________. a. sexual dimorphism b. sexual selection c. diversifying selection d. a cline

a. sexual dimorphism

increase in frequency of beneficial alleles and decrease in deleterious alleles due to selection

adaptive evolution

When male lions reach sexual maturity, they leave their group in search of a new pride. This can alter the allele frequencies of the population through which of the following mechanisms? a. natural selection b. genetic drift c. gene flow d. random mating

c. gene flow

gradual geographic variation across an ecological gradient

cline

What is. the selection pressure that impacts the peppered moth phenotype? a. Daylight Hours b. Soil Composition c. Temperature d. Pollution e. Habitat Destruction

d. Pollution

selection that favors two or more distinct phenotypes

diversifying selection

HbA, HbS=

heterozygote, carrier, & codominance

trait that gives a truthful impression of an individual's fitness

honest signal

mating of closely related individuals

inbreeding

increase in abnormalities and disease in inbreeding populations

inbreeding depression

broader scale evolutionary changes seen over paleontological time

macroevolution

Crossing over occurs during ___________ , when ____________ exchange DNA segments.

meoisis; homologous chromosomes

environmental factor that causes one phenotype to be better than another

selective pressure

phenotypic difference between the males and females of a population

sexual dimorphism

selection that favors average phenotypes

stabilizing selection

In the example in the narrative page, natural selection acted on the character of ___________

thorn length

What is a dimorphism? A. A trait with two distinct forms originating from the interaction of two alleles of a single gene B. A trait consisting of a continuous spectrum of forms influenced by the interaction of multiple genes and multiple alleles C. A trait with three or more distinct forms linked to multiple alleles of a single gene

A. A trait with two distinct forms originating from the interaction of two alleles of a single gene

What is the gene pool? A. All of the alleles of all the genes in a population B. Forms of a gene with slightly different DNA sequences that may encode slightly different versions of the gene's product C. A part of a chromosome that encodes an RNA or protein product in its DNA sequence D. The abundance of a particular allele among members of a population

A. All of the alleles of all the genes in a population

What are potential applications of cladistics and phylogenetics? Select all that apply. A. Correlate evolutionary divergences among a species with the behavior and dispersal patterns of existing populations B. Predict pathogen-host associations and potential disease risk in target populations C. Assess the diversity of target species or groups for conservation efforts D. Assess the relatedness of different species and genera within a family of organisms

A. Correlate evolutionary divergences among a species with the behavior and dispersal patterns of existing populations B. Predict pathogen-host associations and potential disease risk in target populations C. Assess the diversity of target species or groups for conservation efforts D. Assess the relatedness of different species and genera within a family of organisms

Which source of genetic variation introduces potential variation after mating has occurred? A. Fertilization B. Recombination C. Crossing over D. Independent assortment

A. Fertilization

Which of the following factors can lead to microevolution within a population? Select all that apply. A. Gene flow B. Natural selection C. Genetic drift D. Mutation

A. Gene flow B. Natural selection C. Genetic drift D. Mutation

Which of the following are true of genetic drift? Select all that apply. A. Genetic drift involves random changes in allele frequencies. B. Genetic drift can result in the formation of a new species. C. Genetic drift can contribute to allopatric speciation. D. Genetic drift causes physical isolation.

A. Genetic drift involves random changes in allele frequencies. B. Genetic drift can result in the formation of a new species. C. Genetic drift can contribute to allopatric speciation.

Which of these outcomes are examples of reproductive isolation? Select all that apply. A. Hybrid individuals cannot produce offspring B. Reproduction occurs at different times C. Individuals of different species are physically compatible and can engage in sex D. Hybrid individuals or their offspring have similar fitness to the original species E. Mating occurs but fertilization does not occur

A. Hybrid individuals cannot produce offspring B. Reproduction occurs at different times E. Mating occurs but fertilization does not occur

Which factors are necessary for allopatric speciation to occur? Select all that apply. A. Reproductive isolation B. Genetic drift or natural selection C. Geographical isolation D. Gene flow

A. Reproductive isolation B. Genetic drift or natural selection C. Geographical isolation

What are characteristics of sympatric speciation? Select all that apply. A. Reproductive isolation necessary to end gene flow B. Divergence within a population leads to speciation C. Absence of a physical barrier D. Reproductive isolation unnecessary to end gene flow E. Presence of a physical barrier

A. Reproductive isolation necessary to end gene flow B. Divergence within a population leads to speciation C. Absence of a physical barrier

Which statement best describes the change in the T2 allele frequency between timepoint A and timepoint B? A. The allele frequency of the T2 allele increased by 125 percent in 5 years. B. The allele frequency for the T2 allele decreased by 5 percent in 5 years. C. The allele frequency for the T2 allele decreased by 25 percent in 5 years. D. The allele frequency for the T2 allele increased by 20 percent in 5 years.

A. The allele frequency of the T2 allele increased by 125 percent in 5 years.

If no new berry bushes are brought in from elsewhere, which of the following will most likely be true of the population of bushes 5 years after timepoint B? A. There will be no T3 alleles in the population. B. The allele frequencies will be the same as they were at timepoint A. C. The allele frequencies will be the same as they were at timepoint B. D. Allele T2 will cease to exist in the population.

A. There will be no T3 alleles in the population.

Which genotype conveys greater fitness when infected with malaria? A. HbA, HbA B. HbA, HbS C. HbS, HbS

B. HbA, HbS

Which of these interactions are examples of sexual selection? Select all that apply. A. A change in food resources on an island favors finches with medium-sized beaks. Finches with small and large beaks disappear from the island after a few generations. B. Green butterflies are less likely to be eaten than yellow butterflies due to their color. Green butterflies become more numerous than yellow butterflies in the population. C. Male seals compete for territory and access to clusters of female seals. The more aggressive male seals tend to secure the largest territories and clusters. D. Female flies prefer to mate with males that have longer eyestalks. These eyestalks provide no survival advantage, but longer eyestalks become more common over generations.

C. Male seals compete for territory and access to clusters of female seals. The more aggressive male seals tend to secure the largest territories and clusters. D. Female flies prefer to mate with males that have longer eyestalks. These eyestalks provide no survival advantage, but longer eyestalks become more common over generations.

Which of these is an example of a key innovation? A. A new flower color morph arises in a plant population, but an associated pollinator does not distinguish flowers by color. B. A caterpillar of a butterfly species provides honey to an ant colony in order to receive protection and care. C. Co-occurring diploid species of wheat and goatgrass hybridize to form a viable tetraploid offspring that can no longer breed with its parents. D. A founding population of honeycreepers evolves beaks capable of cracking the seed of a tree species in their new habitat.

D. A founding population of honeycreepers evolves beaks capable of cracking the seed of a tree species in their new habitat.

Which of the following best describe a population? A. All organisms living in the same place at the same time. B. All individuals that make up a species that are alive at one time. C. All individuals of one species that have ever lived in a given location. D. A group of individuals of the same species living in the same place at the same time.

D. A group of individuals of the same species living in the same place at the same time.

Which event is least likely to lead to allopatric speciation? A. Construction of a dam that separates two sections of a river B. A new river forms that splits a valley C. Formation of a large urban area that divides a forest D. An entire population migrates together from one side of a canyon to another

D. An entire population migrates together from one side of a canyon to another

What is the process in which two closely interacting species jointly act as selective agents of traits for each other? A. Microevolution B. Macroevolution C. Adaptive radiation D. Coevolution

D. Coevolution

Which source of genetic variation creates individual chromosomes that are a combination of maternal and paternal genes? A. Mutation B. Fertilization C. Independent assortment D. Crossing over

D. Crossing over

The result of independent assortment is gametes that each contain _____. A. all of the maternal chromosomes B. all of the paternal chromosomes C. all of the maternal and paternal chromosomes D. different combinations of maternal and paternal chromosomes

D. different combinations of maternal and paternal chromosomes

What is assortative mating? a. when individuals mate with those who are similar to themselves b. when individuals mate with those who are dissimilar to themselves c. when individuals mate with those who are the most fit in the population d. when individuals mate with those who are least fit in the population

a. when individuals mate with those who are similar to themselves

rate at which a specific allele appears within a population

allele frequency (also, gene frequency)

when individuals tend to mate with those who are phenotypically similar to themselves

assortative mating

Which of the following evolutionary forces can introduce new genetic variation into a population? a. natural selection and genetic drift b. mutation and gene flow c. natural selection and nonrandom mating d. mutation and genetic drift

b. mutation and gene flow

magnification of genetic drift as a result of natural events or catastrophes

bottleneck effect

When closely related individuals mate with each other, or inbreed, the offspring are often not as fit as the offspring of two unrelated individuals. Why? a. Close relatives are genetically incompatible. b. The DNA of close relatives reacts negatively in the offspring. c. Inbreeding can bring together rare, deleterious mutations that lead to harmful phenotypes. d. Inbreeding causes normally silent alleles to be expressed.

c. Inbreeding can bring together rare, deleterious mutations that lead to harmful phenotypes.

What is the difference between micro- and macroevolution? a. Microevolution describes the evolution of small organisms, such as insects, while macroevolution describes the evolution of large organisms, like people and elephants. b. Microevolution describes the evolution of microscopic entities, such as molecules and proteins, while macroevolution describes the evolution of whole organisms. c. Microevolution describes the evolution of organisms in populations, while macroevolution describes the evolution of species over long periods of time. d. Microevolution describes the evolution of organisms over their lifetimes, while macroevolution describes the evolution of organisms over multiple generations.

c. Microevolution describes the evolution of organisms in populations, while macroevolution describes the evolution of species over long periods of time.

Which type of selection results in greater genetic variance in a population? a. stabilizing selection b. directional selection c. diversifying selection d. positive frequency-dependent selection

c. diversifying selection

One of the original Amish colonies rose from a ship of colonists that came from Europe. The ship's captain, who had polydactyly, a rare dominant trait, was one of the original colonists. Today, we see a much higher frequency of polydactyly in the Amish population. This is an example of: a. natural selection b. genetic drift c. founder effect d. b and c

d. b and c

What is a cline? a. the slope of a mountain where a population lives b. the degree to which a mutation helps an individual survive c. the number of individuals in the population d. gradual geographic variation across an ecological gradient

d. gradual geographic variation across an ecological gradient

The good genes hypothesis is a theory that explains what? a. why more fit individuals are more likely to have more offspring b. why alleles that confer beneficial traits or behaviors are selected for by natural selection c. why some deleterious mutations are maintained in the population d. why individuals of one sex develop impressive ornamental traits

d. why individuals of one sex develop impressive ornamental traits

we can say that the animals known as trilobites are _______

extinct

event that initiates an allele frequency change in part of the population, which is not typical of the original population

founder effect

selection that favors phenotypes that are either common (positive frequency-dependent selection) or rare (negative frequency-dependent selection)

frequency-dependent selection

flow of alleles in and out of a population due to the migration of individuals or gametes

gene flow

all of the alleles carried by all of the individuals in the population

gene pool

effect of chance on a population's gene pool

genetic drift

distribution of the different possible genotypes in a population

genetic structure

diversity of alleles and genotypes in a population

genetic variance

differences in the phenotypic variation between populations that are separated geographically

geographical variation

theory of sexual selection that argues individuals develop impressive ornaments to show off their efficient metabolism or ability to fight disease

good genes hypothesis

theory of sexual selection that argues only the fittest individuals can afford costly traits

handicap principle

Selection pressures that operate on natural populations are complex; an allele may be adaptive in one circumstance but ____________ in another.

harmful

protein in the blood that carries oxygen and carbon dioxide, and is responsible for determining the shape of the red blood cell

hemoglobin

fraction of population variation that can be attributed to its genetic variance

heritability

changes in a population's genetic structure

microevolution

overarching evolutionary paradigm that took shape by the 1940s and is generally accepted today

modern synthesis

the coherent understanding of the relationship between natural selection and genetics

modern synthesis

The ___________of a species traces and defines its evolutionary history

phylogeny

What Parasite first grows and multiplies in liver, then in the red blood cells?

plasmodium

study of how selective forces change the allele frequencies in a population over time

population genetics

distribution of phenotypes in a population

population variation

types of selection pressure

predators, availibity of resources, disease, temperature, floods, and storms

individual's ability to survive and reproduce relative to the rest of the population

relative fitness

Allopatric speciation occurs when populations are physically separated and cannot ____________

reproduce

Natural selection can only ___________ not _________

select; create