Genetics Bacterial and Phage Genetics

Question 1

Bacteria are useful to geneticists for a variety of reasons: […]: fewer genes and fewer bases than other organisms. […]: mutations can be observed directly because there is one copy of each gene
[…]: bacterial generation time can be measured in minutes

Answer 1

Genome simplicity;
Haploid genomes; Short generation times

Question 2

Bacteria are useful to geneticists for a variety of reasons: Large numbers of progeny: enormous numbers of progeny allow detection of […]. Ease of propagation: bacterial culture is easy and inexpensive and takes up very […]. […]: mutants are easily created, identified, isolated, and manipulated for study

Answer 2

rare events; little space; Numerous heritable differences

Question 3

Bacteria propagate by binary fission, in which the chromosome […] and a copy is distributed to each of the […]

Answer 3

replicates; progeny cells

Question 4

Minimal medium contains […], a […], some inorganic material, and water. Bacterial species that can grow in minimal medium are called […].

Answer 4

glucose; nitrogen source; prototrophs

Question 5

[…] are bacteria that are mutant for one or more genes that lack the ability to produce a compound or perform a function required for growth. Auxotrophs can grow on a […].
Complete medium contains glucose, a nitrogen source, and all other […] required for growth and reproduction (i.e., amino acids, D N A, R N A, and nucleotides)

Answer 5

Auxotrophs; complete medium; compounds

Question 6

Auxotrophs may also have grown on a […] minimal medium, which has had the specific compound added that the auxotroph cannot […] on its own

Answer 6

supplemented; produce

Question 7

Replica plating is a technique that involves […] some cells from each of the bacterial colonies on an […] to one or more other growth plates

Answer 7

transferring; original growth plate

Question 8

Bacterial genomes are usually composed of a single chromosome, which carries mostly […]. The bacterial chromosome is usually a covalently closed […] of double-stranded DNA

Answer 8

essential genes; circular molecule

Question 9

Most bacteria also carry multiple copies of […], small double-stranded circular DNA molecules containing […] genes

Answer 9

plasmids, nonessential

Question 10

The F (fertility) plasmid contains genes that […] their own transfer from donors to recipients. An R (resistance) plasmid carries […] genes that can be transferred to recipient cells

Answer 10

promote; antibiotic resistance

Question 11

Conjugation is the transfer of DNA from a […] bacterial cell to a recipient through a pilus. Transformation is the uptake of […] from the environment.
Transduction is the transfer of DNA from one […] to another by a viral vector

Answer 11

donor; naked DNA; bacterium

Question 12

Conjugation is controlled by genes carried on the […]
Donor cells possess an F factor and are called […], whereas recipients, called […], lack an F factor. F factor genes direct formation of an […] structure that will move the donor D N A into the recipient cell

Answer 12

F plasmid; F+ cells; F− cells; exporter

Question 13

A large component of the F factor consists of four […]

Answer 13

insertion sequence (IS) elements

Question 13

A large component of the F factor consists of four […]

Answer 13

insertion sequence (IS) elements

Question 14

A conjugation […] forms between the donor and the recipient cells. The […] binds the origin of transfer (oriT) on the F factor and cleaves one […] bond on the T (transfer) strand of the F factor

Answer 14

pilus; relaxosome; phosphodiester

Question 15

In 1953, […] identified donor strains that transferred bacterial genes rather than F factor genes at a high rate
He named these high-frequency recombination, or Hfr, […]. The F factor in Hfr strains integrates into the […] to form the Hfr chromosome

Answer 15

Cavalli-Sforza; strains; bacterial chromosome

Question 16

Conjugation experiments involve […] donor and recipient cells and examining exconjugants. [….] are identified by their growth on a selective growth medium

Answer 16

mixing; Exconjugants

Question 17

Interrupted mating is the […] of conjugation by breaking the conjugation pilus. This process stops […] before the Hfr chromosome can be completely transferred to the recipient cell
Experiments that test for […] at timed intervals (time-of-entry mapping) are used to determine the distances between genes.

Answer 17

cessation; mating; gene transfer

Question 18

The order of gene transfer and time of first appearance of each in exconjugants are related to the distance of the gene from the […]

Answer 18

origin of transfer (oriT)