27.2 Rapid reproduction, mutation, and genetic recombination promote genetic diversity in prokaryotes

Question 1

24) Regarding prokaryotic reproduction, which statement is correct?
A) Prokaryotes form gametes by meiosis.
B) Prokaryotes feature the union of haploid gametes, as do eukaryotes.
C) Prokaryotes exchange some of their genes by conjugation, the union of haploid gametes, and transduction.
D) Mutation is a primary source of variation in prokaryote populations.
E) Prokaryotes skip sexual life cycles because their life cycle is too short.

Answer 1

D) Mutation is a primary source of variation in prokaryote populations.

Question 2

25) Which of these statements about prokaryotes is correct?
A) Bacterial cells conjugate to mutually exchange genetic material.
B) Their genetic material is confined within a nuclear envelope.
C) They divide by binary fission, without mitosis or meiosis.
D) The persistence of bacteria throughout evolutionary time is due to their genetic
homogeneity (i.e., sameness).
E) Genetic variation in bacteria is not known to occur, nor should it occur, because of their asexual mode of reproduction.

Answer 2

C) They divide by binary fission, without mitosis or meiosis.

Question 3

27) If it occurs in the absence of any other type of adaptation listed here, which of these is least
reasonable in terms of promoting bacterial survival over evolutionary time in a
low-glucose environment?
A) increased efficiency at transporting glucose into the cell from the environment
B) increased ability to survive on simple sugars, other than glucose
C) increased ability to synthesize glucose from amino acid precursors
D) increased reliance on glycolytic enzymes
E) increased sensitivity to, and ability to move toward, whatever glucose is present in its habitat

Answer 3

D) increased reliance on glycolytic enzymes

Question 4

30) If new genetic variation in the experimental populations arose solely by spontaneous
mutations, then the most effective process for subsequently increasing the prevalence of the
beneficial mutations in the population over the course of generations is
A) transduction.
B) binary fission.
C) conjugation.
D) transformation.
E) meiosis.

Answer 4

B) binary fission.

Question 5

31) E. coli cells typically make most of their ATP by metabolizing glucose. Under the conditions
of this experiment, what should be true of E. coliʹs generation time (especially early in the
course of the experiment, but less so later on)?
A) Generation time should be the same as in the typical environment.
B) Generation time should be faster than in the typical environment.
C) Generation time should be slower than in the typical environment.
D) It is theoretically impossible to make any predictions about generation time, under these conditions.

Answer 5

C) Generation time should be slower than in the typical environment.

Question 6

32) If the experimental population of E. coli lacks an F factor or F plasmid, and if bacteriophage
are excluded from the bacterial cultures, then which of these is a means by which beneficial
mutations might be transmitted horizontally to other E. coli cells?
A) via sex pili
B) via transduction
C) via conjugation
D) via transformation
E) both A and C above

Answer 6

D) via transformation

Question 7

34) Which term is least closely associated with the others?
A) Hfr cells making use of a sex pilus
B) rolling circle replication
C) the ʺtoilet paperʺ model of replication
D) conjugation involving an F factor
E) recombination involving a bacteriophage

Answer 7

E) recombination involving a bacteriophage