Chapter 6 transformation and transduction

Question 1

________ occurs when a recipient cell takes up a fragment of donor DNA from the surrounding growth medium

Answer 1

Transformation

Question 2

Transformation is a _______ occurring mechanism used to produce accurate maps of bacterial genes. It is also used in the _______ to introduce DNA into microbial, plant, and animal cells

Answer 2

naturally
laboratory

Question 3

Genes that are closely linked are said to be involved in _______, the simultaneous transformation of 2 or more genes

Answer 3

cotransformation

Question 4

What are the steps to transformation? (4)

Answer 4

1) Donor cell lysis
2) Double-stranded donor DNA enters the recipient cell
- one of the strands gets degraded
3) Donor strand aligns with and displaces some of the recipient strand
- forms heteroduplex
4) recipient cell divides forming 1 transformant cell and 1 non transformant cell

Question 5

Double-stranded donor DNA enters the recipient cell where?

Answer 5

receptor site

Question 6

A chromosome that contains all of the transforming strand and recipient strand is called a _______

Answer 6

heteroduplex

Question 7

What are the 6 steps to the lytic cycle?

Answer 7

1) attachment
2) injection
3) replication of phage DNA
- Host DNA breaks down
4) transcription and translation of phage genes
5) assembly / packaging
6) lysis

Question 8

What are the 3 additional steps that differ between the lysogenic cycle and the lytic cycle?

Answer 8

1) Integration: after attachment and injection, the pahge chromosome integrates with the host chromosome via recombination
2) Excision: after multiple cell divisions, the phage DNA excises from the host chromosome
3) Resumption: the phage chromosome enters the lytic cycle and starts replicating

Question 9

A _______ phage is capable of integrating the phage DNA into the host chromosome, becoming lysogenic.

Answer 9

temperate

Question 10

Once integrated into the host chromosome, the phage chromosome is called the _______ (in lysogenic cycle)

Answer 10

prophage

Question 11

transduction is the transfer of genetic material from a donor to a recipient cell by way of a _______

Answer 11

bacteriophage

Question 12

Bacteriophages are composed of an icosahedral _______, hollow protein _______, and sometimes a set of _______

Answer 12

1) head
2) sheath
3) tail fibers

Question 13

Transfer of genetic material from a donor bacterium to a recipient via a phage leads to the production of a _______ bacterial strain

Answer 13

transductant

Question 14

What are the 2 types of transduction?

Answer 14

1) general transduction
2) specialized transduction

Question 15

_______ the transfer of RANDOM bacterial genes, is carried out by bacteriophages that cannot distinguish between phage and bacterial DNA during packing of DNA into new phage particles

Answer 15

generalized transduction

Question 16

_______ is carried out only by temperate phages and the only genes transferred are those close to the integration site

Answer 16

specialized transduction

Question 17

In _______ progeny phages are assembled normally but some phages receive a host DNA fragment instead of phage DNA

Answer 17

generalized transduction

Question 18

In specialized transduction, the integration site is called _____ in the lambda phage and _______ in the E. coli host

Answer 18

attp
attb

Question 19

After integration at the att sites, aberrant excision produces a _______ phage
- contains only galK or bioA gene

Answer 19

specialized transducing

Question 20

The λdgal+ specialized transducing phage includes the galK gene - it can infect host cells but ________

Answer 20

lacks genes needed for lysis and lysogeny

Question 21

The λdbio+ specialized transducing phage includes the bioA gene - it can infect host cells, but ________

Answer 21

lacks the genes needed for lysogeny

Question 22

_______ is the transfer of genetic material between individual bacteria or archaea and other organisms

Answer 22

lateral gene transfer

Question 23

LGT is identified by the presence of DNA-sequence features in regions of a genome that are uniquely different from the rest of the genome = _______

Answer 23

Genomic islands

Question 24

LGT has allowed for rapid organism adaptation to changing environmental conditions by acquiring _______

Answer 24

antibiotic resistance

Question 25

LGT in bacteria can lead to acquired _______, which contain genes for proteins that promote host invasion and genes that produce toxic compounds

Answer 25

pathogenicity islands