BIO Chapter 23 Study quiz

Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent? A) habitat isolation B) temporal isolation C) behavioral isolation D) gametic isolation

Behavioral isolation

An earthquake decimates a ground-squirrel population, killing 98 percent of the squirrels. The surviving population happens to have broader stripes, on average, than the initial population. If broadness of stripes is genetically determined, what effect has the ground-squirrel population experienced during the earthquake? A) directional selection B) disruptive selection C) a founder event D) a genetic bottleneck E) gene flow

D) A genetic bottleneck

Which process led to the formation of the species pairs of Pacific and Caribbean snapping shrimp? A) allopatric speciation by vicariance B) allopatric speciation by dispersal C) sympatric speciation by vicariance D) sympatric speciation by dispersa

A) allopatric speciation by vicariance

Mutation is the only evolutionary mechanism that ________. A) is the ultimate source of variation in natural populations B) does little to change allele frequencies C) decreases fitness D) is more important in eukaryotes than in prokaryotes E) has no effect on genetic variation

A) is the ultimate source of genetic variation in natural populations

Which of these statements is true for a highly inbred population, if there are no other violations of Hardy-Wienberg equilibrium? A. Frequency of homozygous individuals increases, yet frequency of alleles does not change. B. Frequency of heterozygotes increases, and frequency of alleles changes. C. Frequency of homozygous individuals decreases, yet frequecy of alleles does not change.

A. Frequency of homozygous individuals increases, yet frequency of alleles does not change.

Why is genetic drift aptly named? A.It causes allele frequencies to drift up or down randomly B.It occurs when alleles from one population drift into another C.It occurs when mutations drift into a genome D.It occurs when a population drifts into a new habitat

A.It causes allele frequencies to drift up or down randomly

Which of the following statements about species, as defined by the biological species concept are correct? I. Biological species are defined by reproductive isolation. II.Biological species are the model used for grouping extinct forms of life. III. All members of a species can potentially interbreed. A) I and II B) I and III C) II and III

B) I and III I. Biological species are defined by reproductive isolation. & III. All members of a species can potentially interbreed.

When alleles approach a frequency of 1.0 in a population -what does this mean? A) These alleles are lost in this population. B) They are fixed. C) The organisms become haploid and only maintain one copy of each allele

B) They are fixed.

Which of the following does NOT tend to promote speciation? A) the founder effect B) gene flow C) natural sel ection D) polyploidy E) disruptive selection

B) gene flow

Why might females be more choosy regarding mating partners than males?

Because they invest a lot of energy in each egg.

What are homologies? A) Homologies are functionally similar structures -as seen in the wings in birds and beetles. B) Homologies are point mutations in unrelated bacterial species resulting in resistance to antibiotics. C) Homologies are similarities that exists in species descended from a common ancestor.

C) Homologies are similarities that exists in species descended from a common ancestor

Genetic variation ________. A) is created by the direct action of natural selection B) arises in response to changes in the environment C) must be present in a population before natural selection can act upon the population D) tends to be reduced by when diploid organisms produce gametes

C) must be present in a population before natural selection can act upon the population

A small number of birds arrive on an island from a neighboring larger island. This small population begins to adapt to the new food plants available on the island as selection favors those birds with larger beaks. About twice a year, one or two more birds from the neighboring island arrive. These new arrivals ________. A) speed up the process of specia tion B) tend to promote adaptation to the new food plants C) tend to retard adaptation to the new food plants D) represent a colonizing eve

C) tend to retard adaptation to the new food plants

The bicoid protein is a/an ____. A) neurotransmitter B) enzyme C) transcription factor D) a piece of DNA E) a piece of mRN

C) transcription factor

The average depth of the beak in ground finches on one of the Galápagos Islands increased over the years. This change is thought to be correlated with availability of larger seeds only, due to a drought. What type of selection might have affected the beak depth in the ground finch? A.stabilizing B.disruptive C.directional D.all of the above

C.directional

How are two differe nt species most likely to evolve from one ancestral species? A) sympatrically, by a point mutation affecting morphology or behavior B) sympatrically, due to extensive inbreeding C) allopatrically, due to extensive inbreeding D) allopatrically, after the an cestral species has split into two populations

D) allopatrically, after the an cestral species has split into two population

Does gene flow increase or decrease genetic differences among populations?

Decrease

Does gene flow increase or decrease relative fitness in populations?

Depends.

When alleles are transmitted via meiosis and random combination of gametes their frequencies....

Do NOT change over time.

The Dunkers are a religious group that moved from Germany to Pennsylvania in the mid-1700s. They do not marry with members outside their own immediate community. Today, the Dunkers are genetically unique and differ in gene frequencies, at many loci, from all other populations, including those in their original homeland. Which of the following likely explains the genetic uniqueness of this population? A) Population bottleneck Weinberg equilibrium B) heterozygote advantage and stabilizing selection C) sexual selection and inbreeding depression D) mutation and natural selection E) founder effect, inbreeding, and genetic drift

E) founder effect, inbreeding, and genetic drift

Which of the following describes the most likely order of events in allopatric speciation? A) genetic drift, genetic isolation, divergence B) genetic isolation, divergence, genetic drift C) divergence, genetic drift, genetic isolation D) divergence, genetic isolation, genetic drift E) genetic isolation, genetic drift, divergence

E) genetic isolation, genetic drift, divergence

Disruptive selection leads to a/an __________________ in genetic variation?

Increase

28 Most causes of speciation are relatively slow, in that they may take many generations to see changes, with the exception of ________. A) polyploidy B) reinforcement C) colonization D) natural selection

Polyploidy