Question 1

Barnard Davis's U-shaped tube experiment indicated that bacterial genetic exchange requires

Accepted Answer

A)  the exchange of liquid medium between the two sides of the tube.
B)  direct contact between the two bacteria.
C)  mutations to be reverted to wild type.
D)  none of the above B

Question 2

If you were mapping bacterial genes and let the conjugation go for 100 minutes,approximately what percentage of the genome would be transferred?

Accepted Answer

A)  0%
B)  25%
C)  50%
D)  755
E)  100% E

Question 3

In mapping genes using transduction,genes that are _______ will NOT be cotransduced.

Accepted Answer

A)  far apart
B)  mutated
C)  wild type
D)  close together A

Question 4

Which is NOT true of plasmids?

Accepted Answer

A)  They usually carry essential genes for bacterial survival.
B)  Their replication is independent of the chromosomal DNA.
C)  They are used extensively in genetic engineering.
D)  They can provide antibiotic resistance.
E)  They consist of double-stranded DNA.

Question 5

During which bacteriophage life cycle are new phages released from the bacteria by digesting the host cell?

Accepted Answer

A)  lysogenic
B)  lytic
C)  both
D)  neither

Question 6

In a gene mapping experiment,DNA from a strain that is gal+ pro+ lac+ is transformed into an E.coli that is gal− pro− lac−.Some resulting transformants are gal+ lac+ and some are pro+ lac+,but no transformants are gal+ pro+.Which gene is in the middle?

Accepted Answer

A)  gal
B)  lac
C)  pro
D)  cannot be determined

Question 7

The viral enzyme reverse transcriptase is used to

Accepted Answer

A)  convert the viral DNA genome into a new DNA genome.
B)  convert the viral RNA genome into a DNA genome.
C)  digest the host cell.
D)  allow the virus to enter the host cell.

Question 8

Which is NOT an advantage of using bacteria for genetic studies?

Accepted Answer

A)  Haploid genomes allow all mutations to be expressed directly.
B)  Bacteria are of medical importance.
C)  Bacteria have small genomes.
D)  Asexual reproduction makes it easier to isolate genetically pure strains.
E)  all of the above

Question 9

Genetic exchange in bacteria is different from eukaryotic diploid genetic exchange in which way?

Accepted Answer

A)  In bacteria,donated genetic material that is not recombined persists.
B)  In bacteria,genetic exchange results in diploid progeny.
C)  In bacteria,genetic exchange is NOT coupled with reproduction.
D)  all of the above

Question 10

Which of the following F factors can transfer chromosomal DNA?

Accepted Answer

A)  F+
B)  F−
C)  F′
D)  Hfr
E)  F− and Hfr

Exam 6: Bacterial and Viral Genetic Systems