Deck 14: The Origin of Species

Question 1

When plants undergo allopatric speciation,an initial reproductive barrier is often

A)temporal isolation.
B)polyploidy.
C)gametic isolation.
D)pollinator choice.

Answer 1

D

Question 2

The Monterey pine and the Bishop's pine inhabit some of the same areas of central California.The Monterey pine releases pollen in February,while the Bishop's pine does so in April.This is an example of isolation.

A)mechanical
B)temporal
C)habitat
D)postzygotic

Answer 2

B

Question 3

In their 30- year studies of Darwin's finches,the Grants have discovered that while the medium ground finch and cactus finch occasionally form hybrids,these hybrids

A)reproduce with the parent species,showing that ground finches and cactus finches are all one species.
B)usually die before hatching.
C)are unable to produce a song and are therefore unable to find a mate.
D)can only survive during wet years when there are plenty of small seeds.

Answer 3

D

Question 4

The emergence of many diverse species from a common ancestor is called

A)allopatric speciation.
B)hybridization.
C)adaptive radiation.
D)gradualism.

Question 5

Organisms that possess more than two complete sets of chromosomes are said to be

A)polyploid.
B)diploid.
C)hybrids.
D)haploid.

Question 6

Which of the following statements about the Galápagos finches is false?

A)The Galápagos finch species differ in their feeding habitats.
B)The evolution of the Galápagos finches is an excellent example of adaptive radiation.
C)Each island in the Galápagos chain has one and only one isolated,unique species of Darwin's finch.
D)Most speciation events of the Galápagos finches occurred when some finches made it to another island,evolved in isolation,and accumulated enough changes to become a new species.

Question 7

Which of the following types of reproductive barriers separates a pair of species that could interbreed except that one mates at dusk and the other at dawn?

A)habitat isolation
B)behavioral isolation
C)temporal isolation
D)mechanical isolation

Question 8

Which provides the most general and correct description of the idea of a reproductive barrier?

A)a geographic barrier that separates two species and prevents gene flow between them
B)a difference in behavior that keeps two species from interbreeding
C)a biological difference between two species that prevents them from successfully interbreeding
D)any feature (of geography,behavior,or morphology)that keeps one species from mating with another

Question 9

The fossil record shows that for many plant and animal groups,the time between speciation events

A)is equivalent to the length of one hundred generations of a species.
B)varies greatly,but averages 6.5 million years.
C)is usually about 50,000 years.
D)is usually greater than 40 million years.

Question 10

Under the biological species concept,a species is a group of organisms that

A)live together in a location and carry out identical ecological roles.
B)are physically similar.
C)share a recent common ancestor.
D)have the potential to interbreed in nature and produce fertile offspring.

Question 11

Speciation,or the formation of new species,is

A)an event that has occurred only a few times in the history of the planet.
B)a form of microevolution.
C)responsible for the diversity of life.
D)necessary for natural selection and adaptation.

Question 12

The biological species concept is

A)sometimes difficult to put into practice even for present sexual organisms,and useless for asexual organisms and fossils.
B)applicable to all present life forms,but not to fossil organisms whose reproductive behavior cannot be observed.
C)easy to apply to all present sexually reproducing organisms,but harder to apply to asexual organisms and fossils.
D)applicable to all forms of life,past and present.

Question 13

Two species that sometimes mate and produce vigorous but sterile offspring are separated by

A)gametic isolation.
B)hybrid breakdown.
C)reduced hybrid viability.
D)reduced hybrid fertility.

Question 14

Which butterfly has changed gradually but significantly from its ancestor through microevolutionary events that were not part of a speciation event?

A)butterfly A
B)butterfly B
C)butterfly C
D)butterfly D

Question 15

Which of the following would a biologist describe as microevolution?

A)dramatic biological changes,such as the origin of flight,within a taxon
B)a change in the gene pool of a population from one generation to the next
C)the formation of new species
D)the extinction of species

Question 16

Two bird species overlap in a hybrid zone.They are isolated by a slight difference in the male songs and by the females' tendency to select males with the "correct" song.Hybrid offspring tend to have reduced fertility compared to either of the parent species.What effect might natural selection have in this situation?

A)Natural selection could lead to the stronger of the two species taking over and eliminating the other species.
B)Natural selection could lead to the hybrid species taking over and eliminating the weaker parent species.
C)Natural selection might favor males with more distinctive calls and/or females that are more "choosy." As a result,the reproductive barrier between the two species could be reinforced.
D)Natural selection might favor males with less distinctive calls and/or females that are less "choosy."

Question 17

Two species that occasionally mate and produce zygotes,but which have incompatible genes that prevent the resulting embryo from developing,are separated by

A)hybrid breakdown.
B)reduced hybrid fertility.
C)gametic isolation.
D)reduced hybrid viability.

Question 18

Frequently,a group of related species will each have a unique courtship ritual that must be performed correctly for both partners to be willing to mate.Such a ritual constitutes a _, reproductive barrier.

A)behavioral ...prezygotic
B)mechanical ...postzygotic
C)temporal ...prezygotic
D)gametic ...postzygotic

Question 19

Two species interbreed occasionally and produce vigorous,fertile hybrids.When the hybrids breed with each other or with either parent species,however,the offspring are feeble or sterile.These species are separated by

A)gametic isolation.
B)reduced hybrid viability.
C)reduced hybrid fertility.
D)hybrid breakdown.

Question 20

One of the finest available sequences of fossils shows how horses have changed slowly and by subtle steps from small shrub- browsing ancestors to the large,grass- grazing modern horse.A large number of fossil species have been named,and it is often difficult to decide on the identity of a fossil horse because transitional forms are common.This record of evolution best fits the idea of

A)punctuated equilibrium.
B)the gradual model of speciation.
C)hybrid breakdown.
D)adaptive radiation.

Question 21

Ancestral diploid wheat species had 2n = 14 chromosomes.What happened when two of these species hybridized?

A)They produced a hybrid species with 28 chromosomes.
B)They produced a viable,fertile hybrid species with 14 chromosomes.
C)They produced a hybrid species that could not complete mitosis so it did not develop properly.
D)They produced a hybrid species with 14 chromosomes that was sterile,because the chromosomes from the two different parent species did not pair up properly in meiosis.

Question 22

Speciation without geographic isolation is called speciation.

A)sympatric
B)incomplete
C)diversifying
D)allopatric

Question 23

Sympatric speciation commonly occurs through _ in plants,but is more likely to occur through _ in animals.

A)habitat differentiation and sexual selection ...polyploidy
B)self- pollination ...polyploidy and other genetic mechanisms
C)polyploidy ...habitat differentiation and sexual selection
D)asexual reproduction ...chromosome duplications

Question 24

Most polyploid species arise from

A)a single tetraploid parent plant.
B)a single diploid parent plant.
C)a single triploid parent plant.
D)the hybridization of two parent species.

Question 25

Diane Dodd raised different fruit fly populations on different food sources.She found that after about 40 generations,the evolution of reproductive isolation was under way.The mechanism of evolution responsible for this was

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

Question 26

The emergence of a new plant species over a brief period of time,followed by a long period of little change,is consistent with which of the following theories?

A)the gradual model of speciation
B)adaptive radiation
C)allopatric speciation
D)punctuated equilibrium

Question 27

In which of the following situations would speciation be most likely to occur?

A)A population of juniper shrubs is split in two by a canyon.Every year,strong winds carry a small amount of the shrub's pollen across the canyon.
B)Seven monkeys escape from an amusement park and zoo in South Florida.To everyone's surprise,they establish a small but viable population,coexisting successfully with humans in a partly suburban environment very different from their native African habitat.
C)Bighorn sheep occupy mountains from Canada through Death Valley in Southern California,interbreeding all the way.The populations at the two ends of the range live in very different environments.
D)A Japanese mollusk species whose larvae are often carried from port to port in ship bilge water now flourishes in San Francisco Bay,a busy commercial port.

Question 28

Which of the following statements regarding the definition of species is false?

A)Under the biological species concept,the gap between species is maintained by reproductive isolation.
B)The phylogenetic species concept defines a species as a set of organisms that shares a common ancestor and forms one branch on the tree of life.
C)The morphological species concept relies upon comparing the DNA sequences of organisms.
D)The ecological species concept identifies species in terms of their ecological niches.

Question 29

When a tetraploid flower pollinates a diploid flower of the parental species,the resulting offspring will be

A)triploid and sterile.
B)triploid and fertile.
C)pentaploid and sterile.
D)diploid and fertile.

Question 30

Which of the following types of reproductive barriers separates two species of sea cucumbers,whose sperm and eggs often bump into each other but do not cross- fertilize because of incompatible proteins on their surfaces?

A)gametic isolation
B)temporal isolation
C)mechanical isolation
D)habitat isolation

Question 31

Which of the following statements about plant speciation and hybridization is false?

A)Plant biologists estimate that 80% of all living plant species are descended from ancestors that formed by polyploid speciation.
B)Bread wheat grown widely today is the result of several hybridization events.
C)Bread wheat is the ancestral diploid wheat plant.
D)Modern plant geneticists use chemicals to induce meiotic and mitotic errors to try to create new hybrid plants with special qualities.

Question 32

Which of the following would tend to promote adaptive radiation?

A)A single species goes extinct,but it has several competitors that quickly expand to assume its ecological roles.
B)An organism colonizes an isolated area that is habitable but relatively devoid of life.
C)An organism colonizes an area that already has a high level of existing species diversity.
D)An organism has a very stable set of features and capabilities over long spans of evolutionary time.

Question 33

Which of the following types of reproductive barriers separates a pair of insect species that could interbreed except that one lives on goldenrod plants and the other on autumn daisies in the same general area?

A)habitat isolation
B)gametic isolation
C)behavioral isolation
D)temporal isolation

Question 34

Which of the following types of reproductive barriers separates two flowering plant species that could interbreed except that one has a deep flower tube and is pollinated by bumblebees,whereas the other has a short,narrow flower tube and is pollinated by honeybees?

A)behavioral isolation
B)habitat isolation
C)mechanical isolation
D)gametic isolation

Question 35

Which species of wheat shown is polyploid?

A)T.monococcum
B)the AB sterile hybrid
C)T.tauschii
D)T.turgidun

Question 36

Which of the following descriptions best represents the gradual model of speciation?

A)Species undergo little change over long periods interrupted only by short periods of rapid change.
B)An isolated population differentiates quickly from its parent stock as it adapts to its local environment.
C)Speciation occurs regularly as a result of the accumulation of many small changes.
D)Speciation occurs under unusual circumstances and therefore transitional fossils are hard to find.

Question 37

Two populations of organisms belong to the same biological species when they

A)can't mate with each other,because mating occurs at different times.
B)encounter each other,mate,and produce viable,fertile offspring under natural conditions.
C)use different types of behaviors or physical features to attract mates.
D)have anatomical features that make it difficult for organisms from the different populations to mate.

Question 38

One of the key contributions of the punctuated equilibrium model is that it helps explain

A)why transitional fossils are more common than Darwin would have predicted.
B)why large,widespread populations tend to be the ones that evolve most rapidly and unpredictably.
C)why transitional fossils tend to be rare and certain common fossil species remain unchanged for long time spans.
D)how new species arise from hybridization events.

Question 39

Diane Dodd's experiments using fruit flies demonstrated that

A)formation of a reproductive barrier between two populations is more likely if they experience and adapt to different environmental conditions.
B)reproductive barriers usually are absolute-either two populations are fully willing and able to interbreed,or they are strictly separated by a fully effective reproductive barrier.
C)the evolution of reproductive barriers occurs much too slowly to produce measurable effects in the laboratory.
D)new species can form in a single generation by the production of new reproductive structures.

Question 40

Uplift and formation of a mountain range divides a freshwater snail species into two isolated populations.Erosion eventually lowers the mountain range and brings the two populations together again,but when they mate,the resulting hybrids all produce sterile young.This scenario is an example of

A)sympatric speciation.
B)diversifying speciation.
C)incomplete speciation.
D)allopatric speciation.

Question 41

In a hybrid zone,can occur if the reproductive barrier between two species is weak,as seen among cichlids in the murky waters of modern Lake Victoria.

A)fusion
B)allopatric speciation
C)reproductive isolation
D)reinforcement

Question 42

Which of the following types of reproductive barriers separates a pair of moth species that could interbreed except that the females' mating pheromones are not attractive to the males of the other species?

A)gametic isolation
B)behavioral isolation
C)mechanical isolation
D)temporal isolation

Question 43

The suggests that speciation occurs in brief spurts.

A)adaptive model of the origin of species
B)gradual model of the origin of species
C)allopatric speciation model
D)punctuated equilibrium model

Question 44

The geographic isolation of a population from other members of the species and the subsequent evolution of reproductive barriers between it and the parent species describes speciation.

A)biogeographic
B)sympatric
C)punctuated
D)allopatric