Deck 8: Genetic Analysis and Mapping in Bacteria and Bacteriophages

Question 1

Transduction is a form of recombination in bacteria that involves ________.

A)5-bromouracil
B)F plasmids
C)bacteriophages
D)fertility factors
E)physical contact between the bacteria involved

Answer 1

C

Question 2

In what way was the interrupted mating technique used to generate a genetic map in E.Coli based on time?

Answer 2

The interrupted mating technique showed that genes were passed in a linear fashion from the Hfr bacterial strain to an F? strain.By interrupting the mating tube,it could be determined when (in minutes)genes were transferred.

Question 3

Describe how different strains of E.Coli can reveal different linkage arrangements of genes in Hfr crosses.

Answer 3

Different strains may have different F factors and therefore different initiation points for chromosome transfer.

Question 4

Jacob,Wollman,and others developed a linkage map of E.Coli that is based on time.What form of recombination is involved in generating a linkage map based on time?

Question 5

Explain the composition and use of minimal medium in the study of bacterial genetics.

Question 6

What are prototrophs?

Question 7

In general,what two methods are used to grow bacteria in the laboratory?

Question 8

Distinguish between F? and F? bacteria.

Question 9

How does an auxotroph differ from a prototroph?

Question 10

Name two forms of recombination in bacteria.

A)lytic and lysogenic
B)auxotrophic and prototrophic
C)conjugation and transduction
D)mixed and generalized
E)insertion and replication

Question 11

What is the role of the F factor in bacterial recombination?

Question 12

The clearing made by bacteriophages in a "lawn" of bacteria on an agar plate is called a ________.

A)clear zone
B)lysogenic zone
C)prophage
D)plaque
E)host range

Question 13

Name the typical phases of the bacterial growth cycle in liquid culture medium.

Question 14

Name the general category into which double-stranded circular extrachromosomal DNA elements such as F factors,ColE1,and R would fall.

A)capsid
B)r-determinant
C)plaque
D)partial diploid
E)plasmid

Question 15

What is a merozygote?

Question 16

Bacteriophages engage in two interactive cycles with bacteria.What are these cycles?

A)lytic and lysogenic
B)insertion and replication
C)auxotrophic and prototrophic
D)heteroduplex and homoduplex
E)negative and positive

Question 17

Assume that the gene trpA in an auxotrophic strain of E.Coli is located at 27 minutes,whereas the gene pyrE is located at 81 minutes.

Question 18

Temperate phages are those that can enter either the ________ or ________ cycle.

A)lytic; lysogenic
B)virulent; avirulent
C)functional; nonfunctional
D)former; nonformer
E)complementing; competing

Question 19

A bacteriophage that is capable of entering either a lytic or lysogenic cycle is called a(an)________.

A)temperate bacteriophage
B)virulent bacteriophage
C)plasmid
D)episome
E)plaque-forming unit

Question 20

What is a form of recombination in bacteria that involves the F plasmid?

Question 21

Present the general structural features of a plasmid and give an example.

Question 22

In a bacterial cross in which the donor (Hfr)is a??? and the recipient strain (F?)is a???,it is expected that recombinant bacteria will all be a???.

Question 23

What is a bacteriophage?

Question 24

An Hfr cell can initiate chromosome transfer from one E.Coli to another.

Question 25

What experimental observation demonstrated that genes are involved in the integration of foreign DNA into the bacterial chromosome?

Question 26

Lysogeny is an important phenomenon in bacteria and phages.Briefly describe lysogeny.

Question 27

Assume that one counted 67 plaques on a bacterial plate where 0.1 ml of a 10?? dilution of phage was added to bacterial culture.What is the initial concentration of the undiluted phage?

Question 28

Bacteriophages that cannot undergo lysogeny but can infect bacteria are called ________.

Question 29

When a bacteriophage genome incorporates itself into the chromosome of the host,that phage genome is referred to as a(an)________.

Question 30

A form of bacterial recombination that involves a viral intermediate is called ________.

Question 31

Bacteria that are in a particular physiological state to become transformed are called ________.

Question 32

What is a significant difference between a lytic and a lysogenic cycle?

Question 33

If two different auxotrophic strains are placed in a liquid medium culture tube,prototrophic strains can sometimes be subsequently recovered.Name several mechanisms by which this is possible.

Question 34

What are the roles of the recBCD genes?

Question 35

What is the consequence of a mutation in the recA gene in bacteria?

Question 36

What is meant by the term cotransformation?

Question 37

Explain what is meant by the term heteroduplex in the context of bacterial transformation.

Question 38

Compare and contrast bacteriophage lysis and lysogeny.

Question 39

What term is used to describe the phenomenon in which a bacteriophage genome incorporates its genome into the chromosome of the host?

Question 40

The "interrupted mating technique" provides a genetic map in Drosophila.

Question 41

Lysogeny is a process that occurs during transformation and conjugation.

Question 42

Viral mutations and variants are often categorized by changes in host range and/or plaque morphology.

Question 43

Lysogeny is most likely associated with transduction.

Question 44

A symbiotic relationship between a phage and a bacterium apparently occurs in the process of lysogeny.

Question 45

Cotransduction of genes is an indication that the genes are linked.

Question 46

R plasmids often contain genes for antibody production.

Question 47

A plaque is a substance that causes mutation in bacteria.