Biology: The Dynamic Science

Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter 22

Speciation - all with Video Answers

Educators

Chapter Questions

Problem 1

The biological species concept defines species on the basis of:
a. reproductive characteristics.
b. biochemical characteristics.
c. morphological characteristics.
d. behavioral characteristics.
e. all of the above.

Joanna Quigley

Joanna Quigley

Numerade Educator

Problem 2

Biologists can apply the biological species concept only to species that:
a. reproduce asexually.
b. lived in the past.
c. are allopatric to each other
d. hybridize in captivity.
e. reproduce sexually.

Joanna Quigley

Numerade Educator

Problem 3

A characteristic that exhibits smooth changes in populations distributed along a geographical gradient is called a:
a. ring species.
b. hybrid.
c. cline.
d. hybrid breakdown.
e. subspecies.

Joanna Quigley

Numerade Educator

Problem 4

If two species of holly (genus Ilex) flower during different months, their gene pools may be kept separate by:
a. mechanical isolation.
b. ecological isolation.
c. gametic isolation.
d. temporal isolation.
e. behavioral isolation.

Joanna Quigley

Numerade Educator

Problem 5

Prezygotic isolating mechanisms:
a. reduce the fitness of hybrid offspring.
b. generally prevent individuals of different species from producing zygotes.
c. are found only in animals.
d. are found only in plants.
e. are observed only in organisms that reproduce asexually.

Joanna Quigley

Numerade Educator

Problem 6

In the model of allopatric speciation, the geographical separation of two populations:
a. is sufficient for speciation to occur.
b. occurs only after speciation is complete.
c. allows gene flow between them.
d. reduces the relative fitness of hybrid offspring.
e. inhibits gene flow between them.

Joanna Quigley

Numerade Educator

Problem 7

Adjacent populations that produce hybrid offspring with low relative fitness may be undergoing:
a. clinal isolation.
b. parapatric speciation.
c. allopatric speciation.
d. sympatric speciation.
e. geographical isolation.

Joanna Quigley

Numerade Educator

Problem 8

An animal breeder, attempting to cross a llama with an alpaca for finer wool, found that the hybrid offspring rarely lived more than a few weeks. This outcome probably resulted from:
a. genetic drift.
b. prezygotic reproductive isolation.
c. postzygotic reproductive isolation.
d. sympatric speciation.
e. polyploidy.

Joanna Quigley

Numerade Educator

Problem 9

Which of the following could be an example of allopolyploidy?
One parent has 8 chromosomes, the other has $10,$ and their offspring have 36
b. Gametes and somatic cells have the same number of chromosomes.
c. Chromosome number increases by one in a gamete and in the offspring it produces.
d. Chromosome number decreases by one in a gamete and in the offspring it produces.
e. Chromosome number in the offspring is exactly half of what it is in the parents.

Joanna Quigley

Numerade Educator

Problem 10

Which of the following genetic characteristics is shared by humans and chimpanzees?
a. They have the same number of chromosomes.
b. The position of the centromere on human chromosome 2 matches the position of a centromere on a chimpanzee chromosome.
c. A fusion of ancestral chromosomes formed chromosome 2.
d. Centromeres on all of their chromosomes fall within inverted chromosome segments.
e. all of the above

Joanna Quigley

Numerade Educator