chapter 6

Question 1

What are the processes by which bacteria exchange genes?

Answer 1

1. Conjugation
2. Transformation
3. Transduction

Question 2

Can the gene exchange processes be used to map genes producing mutant phenotypes?

Answer 2

Yes

Question 3

What are some applications of bacterial genetics?

Answer 3

1. Genome sequencing
2. Forensic analyses
3. Genetic Medicines
4. Systems Biology
5. Biofuels Production

Question 4

What is a defining feature of bacteria?

Answer 4

Genomic DNA is not confined to a membrane-bound nucleus

Question 5

What type of organisms do bacteria belong to?

Answer 5

Prokaryotic organisms

Question 6

What is the typical structure of a bacterial genome?

Answer 6

Typically limited to a single large circular chromosome

Question 7

What are plasmids?

Answer 7

Small circular DNA entities that harbor additional genes

Question 8

What are bacteriophages?

Answer 8

Viruses that can parasitize bacteria

Question 9

What is a prototrophic bacterium?

Answer 9

Cells that can grow in minimal medium containing only the bare essentials

Question 10

What is an auxotrophic bacterium?

Answer 10

Mutant cells that cannot grow in medium lacking a specific building block

Question 11

What are the three main methods of gene transfer in bacteria?

Answer 11

1. Conjugation
2. Transformation
3. Transduction

Question 12

What is conjugation in bacteria?

Answer 12

Fusion of two cells where a donor cell transfers DNA to a recipient cell

Question 13

What does transformation involve?

Answer 13

Scavenging DNA from the external environment and incorporating it into a bacterium’s genome

Question 14

What is transduction?

Answer 14

A bacteriophage picks up a piece of DNA from a bacterial host and transfers it to a second host cell

Question 15

Who were Joshua Lederberg and Edward Tatum?

Answer 15

Researchers who confirmed that bacteria can undergo a form of sexual reproduction and recombination

Question 16

What is the fertility factor (F)?

Answer 16

A plasmid that directs the formation of pili for bacterial conjugation

Question 17

What is an Hfr strain?

Answer 17

A high frequency recombination strain that donates part of its chromosome during conjugation

Question 18

What is the significance of the F factor in bacterial genetics?

Answer 18

It integrates into the host chromosome and can transfer genes during conjugation

Question 19

What is the purpose of tracking time of marker entry in bacterial genetics?

Answer 19

To generate a chromosome map based on the order of allele transfer

Question 20

What is the result of a single crossover event in bacterial recombination?

Answer 20

It breaks the chromosomal ring and is unviable

Question 21

What are R plasmids?

Answer 21

Plasmids that confer resistance to multiple antibiotics

Question 22

What is bacterial transformation?

Answer 22

Permanent change of bacteria by the uptake of DNA from the environment

Question 23

Fill in the blank: Bacteria can obtain new genetic information from their _______.

Answer 23

[environment]

Question 24

True or False: Bacteria reproduce sexually like eukaryotes.

Answer 24

False

Question 25

What is bacterial transformation?

Answer 25

Permanent change of bacteria by the uptake of DNA from a distinct genotype ## Footnote This DNA can be from living or dead cells of the same or different species.

Question 26

What is the source of DNA in bacterial transformation?

Answer 26

DNA can be from living or dead cells of the same or different species.

Question 27

How is the uptaken DNA incorporated into the bacterial chromosome?

Answer 27

By a process similar to the transfer of genes from an Hfr to a F- cell.

Question 28

What is an example of bacterial transformation in the lab?

Answer 28

Transforming bacteria with a plasmid that contains and expresses the Green Fluorescent Protein gene.

Question 29

What are the uses of transformed bacteria?

Answer 29

To store a plasmid, replicate a plasmid, and express a gene.

Question 30

What is metagenomics?

Answer 30

A way to identify genes encoding enzymes that evolved to break down plant materials.

Question 31

What is the significance of highly active enzymes in biofuel production?

Answer 31

They are needed to scale-up the ability to make biofuels from non-food crops.

Question 32

What is transduction in the context of bacteriophages?

Answer 32

When a phage picks up DNA from a bacterium and transfers this sequence to another bacterium.

Question 33

Who discovered the process of transduction?

Answer 33

Joshua Lederberg and Norton Zinder in 1951.

Question 34

What are virulent phages?

Answer 34

Phages that infect and immediately lyse or kill the host cell.

Question 35

What are temperate phages?

Answer 35

Phages that can remain in the host for a time without killing it.

Question 36

What is a prophage?

Answer 36

A phage incorporated into a bacterial chromosome.

Question 37

What is a lysogenic bacterium?

Answer 37

A bacterium that has a non-active phage in its chromosome.

Question 38

What are the two types of transduction?

Answer 38

* Generalized * Specialized

Question 39

What occurs during generalized transduction?

Answer 39

Random incorporation of bacterial DNA into phage heads.

Question 40

What is the outcome of a single phage infection of a bacterial cell?

Answer 40

Production of numerous descendant phages and formation of a plaque.

Question 41

What is the role of faulty phage head stuffing in generalized transduction?

Answer 41

It leads to the transduction of new bacteria by bacterial genes.

Question 42

How can linkage information for bacterial genes be calculated?

Answer 42

From high cotransduction frequencies, inferring close linkage.

Question 43

What is specialized transduction?

Answer 43

When certain phages carry only specific bacterial genes to a recipient cell.

Question 44

What process allows a specialized transducer phage to pick up adjacent bacterial genes?

Answer 44

Faulty outlooping.

Question 45

What is the effect of a cytoplasmic repressor on specialized transduction?

Answer 45

Absence of a cytoplasmic repressor allows for faulty outlooping.