Mastering Biology Chapter 24

Plant species F has a diploid number of 8. Plant species G has a diploid number of 10. what would be the diploid number of an allopolyploid hybrid of species F and species G?

18 4 from F, 5 from G, 9 total, times 2

morphological and phylogenetic

species acceptance criteria can be subjective; accommodates asexual reproduction

postzygotic barriers

reduced hybrid fertility; reduced hybrid viability

morphological

relies on similarities in structures

biological

not applicable to extinct species

reduced hybrid fertility

offspring of two newts are sterile

gametic isolation

a coral's sperm can't fertilize another's eggs

Why are the large finches now living on the Galapagos islands different from the original source population from a nearby island? a. all three answers are correct b. natural selection favored individuals that were more fit in the new environment c. genetic drift occurred in the two populations d. the separation of habitats reduced gene flow between the populations

a. all three answers are correct

two animals are considered members of different species if they: a. cannot mate and produce viable, fertile offspring b. are members of different populations c. are geographically isolated d. live in different habitats e. look different

a. cannot mate and produce viable, fertile offspring

A population of birds colonizes an area in which the insects upon which they feed live inside trees. Which of the following events accounts for an observed increase in average beak size in the bird population over time? a. increased fitness of large-beaked birds, leading to natural selection b. decreased fitness of the insects, allowing the birds to catch them more easily c. increased fitness of the large-beaked birds, creating a new species d. decreased fitness of small-beaked birds, creating a new species

a. increased fitness of large-beaked birds, leading to natural selection

Gametes from two plant species combine and produce a haploid zygote, and that zygote develops into a haploid, hybrid plant. Why is the hybrid plant sterile? a. meiosis cannot occur b. the cells do not contain homologous chromosomes c. mitosis cannot occur d. the gametes produced cannot combine with the gametes of other plants e. the plant cannot grow and reproduce asexually

a. meiosis cannot occur b. the cells do not contain homologous chromosomes

What is genetic drift? a. the production of an evolutionary independent group of organisms b. a change in allele frequencies caused by random events c. the motion of continental plates over time d. the physical splitting of a habitat

b. a change in allele frequencies caused by random events

The sequence of events illustrated in this figure results in a fertile hybrid plant called an allopolyploid. Which of the following statements is the most complete description of an allopolyploid? a. it contains more than one pair of homologous chromosomes b. it contains more than two sets of chromosomes, which are derived from two species c. it contains more than two sets of chromosomes, which are derived from a single species d. it is able to sexually reproduce with two or more other plant species because of its diverse set of chromosomes

b. it contains more than two sets of chromosomes, which are derived from two species

A subset of a population of bird leaves its habitat on the mainland and colonizes a nearby island. The birds, after a period of time, become reproductively isolated. The island sinks and the population of birds that lived on the island returns to its original habitat. Which of the following statements about these bird populations is true? a. the populations will be able to interbreed even though they are different species b. the populations will not be able to interbreed because they are different species c. the populations were sympatric while they diverged d. the birds were separated by a vicariance event

b. the populations will not be able to interbreed because they are different species

phylogenetic

based on evolutionary history

behavioral isolation example

beetle mating displays show different spot patterns

prezygotic barriers

behavioral isolation; mechanical isolation; habitat isolation; temporal isolation; gametic isolation

temporal isolation

birds are active during different times of day

Mass extinctions create conditions that promote: a. paedomorphosis b. microevolution c. adaptive radiation d. gene flow e. genetic drift

c. adaptive radiation

The different finch species found on the Galapagos Islands probably arose as a result of: a. mass extinction b. paedomorphosis c. adaptive radiation d. artificial selection e. gene flow

c. adaptive radiation

_______ is rapid speciation under conditions in which there is little competition. a. genetic drift b. paedomorphosis c. adaptive radiation d. microevolution e. gene flow

c. adaptive radiation

A certain species of salamander was split into two populations by a wide, dry valley, and the populations began to diverge from each other. After a period of time, some members of the two populations began to interbreed in a hybrid zone at the southern end of the valley. Only weak reproductive barriers existed by this time, so the two populations could freely interbreed and re-establish gene flow. This outcome in a hybrid zone is known as: a. speciation b. stability c. fusion d. punctuated equilibrium e. reinforcement

c. fusion

What is the most important factor that holds a gene pool of a species together and prevent speciation? a. sexual selection b. prezygotic barriers c. gene flow d. hybridization e. behavioral isolation

c. gene flow

Which of the following statements about reinforcement is true? a. reinforcement increases the number of intermediate phenotypes b. reinforcement decreases the morphological difference between two ancient species c. reinforcement is a type of natural selection d. reinforcement is also called dispersive selection

c. reinforcement is a type of natural selection

Hybrid zones provide an opportunity to investigate: a. mutations b. allopatric speciation c. the evolution of reproductive isolation d. punctuated equilibrium e. polyploidy

c. the evolution of reproductive isolation

What roles does nondisjunction play in the formation of a fertile allopolyploid hybrid? a. it allows gametes of the two parent species to combine b. it causes the chromosomes to line up at the center of the cell during mitosis c. it breaks down chromosomes that don't exist as homologous pairs d. it doubles the chromosome number in the hybrid

d. it doubles the chromosome number in the hybrid

According to the _______ model, evolution occurs in spurts; species evolve relatively rapidly then remain unchanged for long periods. a. geographic isolation b. adaptive radiation c. nondisjuction d. punctuated equilibrium e. gradualist

d. punctuated equilibrium

The appearance of an evolutionary novelty promotes: a. mass extinction b. gene flow c. mutation d. paedomorphosis e. adaptive radiaiton

e. adaptive radiation

Feathers either play a role, or may have played a role, in: a. gliding b. courtship c. extended hops d. flight e. all of the above

e. all of the above

The last ice age produced many different species mainly because populations dispersed and colonized new habitats. true or false?

false

mechanical isolation example

flowers accommodate different insect pollinators

reduced hybrid viability

lion-tiger hybrids don't react maturity

A flood that separates a population of frogs onto opposite sides of a lake is an example of a vicariance event that may result in allopatric speciation. true or false?

true

habitat isolation

two fish species spawn at different depths

morphological, phylogenetic, and biological

used by scientists in classification