Chapter 14

Question 1

A type of genetic recombination that occurs only at specific sequences

Answer 1

site-specific recombination

Question 2

A transposon that moves via an RNA intermediate that is converted back to DNA by reverse transcriptase.

Answer 2

transposon and transposable element

Question 3

Bacteriophage infection in which the DNA is incorporated into the host chromosome or as an autonomously replicating plasmid with most of its genes repressed

Answer 3

lysogenic pathway

Question 4

Parasitic bacteriophage infection in which the DNA is replicated and packaged into phage heads, and the host cell is destroyed by lysis to disperse the progeny. Compare lysogenic pathway

Answer 4

lytic pathway

Question 5

A bacteriophage-encoded site-specific recombination system that promotes circularization of the phage P1 genome and aids in proper segregation at cell division of phage plasmids in the lysogenic state.

Answer 5

Cre-lox

Question 6

The expression of alternative primary cell surface antigens used by some pathogenic bacteria and parasitic protists as a means of eluding a host’s immune system.

Answer 6

phase variation

Question 7

The location on a chromosome of a transposon before it moves to a target site.

Answer 7

donor site

Question 8

The location on a chromosome where a transposon inserts itself

Answer 8

target site

Question 9

Transposon-encoded enzymes that catalyze the reactions required for the transposon to excise itself from the donor site and insert itself into the target site. These reactions typically include hydrolysis of a specific phosphodiester bond and transesterification involving attack of the liberated 3′ hydroxyl on another phosphodiester bond.

Answer 9

transposase

Question 10

The DNA is
excised from its donor site, then completely
inserted in the target site.

Answer 10

cut and paste mechanism

Question 11

The transposon is
linked to the target before it is excised.

Replication then occurs, resulting in two
copies of the transposable element, one at the donor and one at the target site

Answer 11

replicative transposition

Question 12

an RNA intermediate is
used to create a new transposon via reverse
transcription which is then copied to the
target site

Answer 12

Transposition with RNA intermediate

Question 13

A transposon that moves via an RNA intermediate that is converted back to DNA by reverse transcriptase.

Answer 13

retrotransposon (retrotransposable element)

Question 14

An RNA-directed DNA polymerase in retroviruses; capable of making DNA complementary to an RNA.

Answer 14

reverse transcriptase

Question 15

A retrotransposon that moves via a double-stranded cDNA copy of its mRNA transcript. The cDNA inserts itself into the target site in a reaction catalyzed by a recombinase or integrase.

Answer 15

extrachromosomally primed (EP) retrotransposon

Question 16

An enzyme that catalyzes the insertion of a retrovirus or retrotransposon into its target site.

Answer 16

integrase

Question 17

A specific base sequence at either end of a transposable segment of DNA.

Answer 17

insertion sequence

Question 17

A transposon that consists of two insertion elements flanking one or more genes not required for transposition, such as antibiotic-resistance genes

Answer 17

composite transposon

Question 18

A viruslike transposon with a large genome including genes not required for transposition

Answer 18

complex transposon

Question 19

Another elegant example of SSR that facilitates DNA replication is the

Answer 19

2 micro plasmid

Question 20

An RNA virus containing a reverse transcriptase.

Answer 20

retrovirus

Question 21

A duplex DNA with one strand identical to a specific mRNA (with T residues generally substituting for the U residues in the mRNA), used in DNA cloning; usually made by reverse transcriptase

Answer 21

complementary DNA (cDNA)

Question 22

A protein secondary structure in which the amino acid residues D, D, and E (two aspartate residues and a glutamine residue) form the catalytic core in the active site of phosphoryltransferase enzymes such as integrases and transposases

Answer 22

DDE motif