Chapter 11 recombination

Question 1

_______ is the exchange of genetic material between homologous DNA molecules

Answer 1

homologous recombination

Question 2

In bacteria, and similarly in archaea, homologous recombination occurs during _______ and, as a consequence of double-strand break repair

Answer 2

conjugation

Question 3

In eukaryotes, homologous recombination occurs during _______

Answer 3

prophase I of meiosis

Question 4

the _______ pathway is the system of homologous recombination in bacteria

Answer 4

RecBCD

Question 5

What is the process of the RecBCD pathway of recombination? (3)

Answer 5

1) Rec A protein binds to double stranded break
2) Rec BCD attatches leading to single strand invasion and D loop formation
3) Ruv AB and Ruv C bind and complete recombination

Question 6

What proteins are needed to carry out double stranded break model of meiotic recombination part 1?

Answer 6

1) Spo11
2) Mrx and Exol
3) Rad51 and Dmc1

Question 7

What is the process of double-stranded break model of meiotic recombination? part 1

Answer 7

1) Spo11 generates an asymmetric double-strand cut in one of the chromatids
2) Mrx and Exol digest single strands
3) Rad51 and Dmc1 facilitate strand invasion and D loop formation
4) Holliday junction created

Question 8

What proteins are needed to carry out double stranded break model of meiotic recombination part 2?

Answer 8

1) Rad52
2) Rad 59
3) DNA polymerase
4) Ligase

Question 9

What is the process of double-stranded break model of meiotic recombination? part 2

Answer 9

1) Rad52 and Rad59 assist DNA synthesis of the invading strand
2) the 3’ end of the invading stand joins to the 5’ end of its original chromatid by ligation
3) non-sister chromatids are now connected by double Holliday junctions

Question 10

A _______ is double-stranded DNA formed from single-stranded pieces of DNA of different homologs

Answer 10

heteroduplex

Question 11

Holliday Junction Resolution can occur two ways:

Answer 11

1) Same sense resolution
2) opposite sense resolution

Question 12

In _______ two N/S cuts or two E/W cuts occur and DNA outside the flanking markers to not recombine

Answer 12

same sense resolution

Question 13

in _______ 1 N/S cut and 1 E/W cut occurs and results in major changes in chromosome segments, ends swap

Answer 13

opposite sense resolution

Question 14

Which is more common, same sense or opposite sense resolution?

Answer 14

opposite sense

Question 15

_______ are DNA sequences that can move within the genome by an enzyme-driven process

Answer 15

transposable genetic elements

Question 16

transposable genetic elements are moved within the genome by _______

Answer 16

transposition

Question 17

What are the two ways that transposable genetic elements move?

Answer 17

1) excision
2) duplication

Question 18

A transposable element can cause a mutation if it inserts into a wild-type allele and disrupts its function, this is called _______

Answer 18

insertional inactivation

Question 19

What are the two elements that all transposable elements have in common?

Answer 19

1) terminal inverted repeats
2) flanking direct repeats

Question 20

What is the process of transposition?

Answer 20

1) staggered cuts are made by transposase
2) double-stranded transposable element is inserted into the new site
3) DNA is replicated to fill single-stranded gaps

Question 21

_______ transpose as DNA sequences and may be replicative or non-replicative

Answer 21

DNA transposons

Question 22

________ are composed of DNA but transpose through an RNA intermediate

Answer 22

retrotransposons

Question 23

the RNA of a retrotransposon is copied back into DNA by _______

Answer 23

reverse trancriptase

Question 24

_______ excises a transposable element from one position and inserts it into a new location

Answer 24

non-replicative transposition
- cut and paste

Question 25

______ are simple transposable elements containing terminal inverted repeats surrounding a gene encoding transposase

Answer 25

insertion sequences

Question 26

_______ carry a transposase gene, two flanking IS elements, and one or more additional genes

Answer 26

composite transposons

Question 27

_______ carry a transposase gene, and one or more additional genes but lack IS elements

Answer 27

non-composite transposons

Question 28

Nearly _______ of the human genome is composed of transposable DNA

Answer 28

half

Question 29

_______ infect eukaryotic cells and have genomes composed of single-stranded RNA

Answer 29

retroviruses

Question 30

The gene(s) carried on retrotransposons are flanked by _______

Answer 30

long terminal repeats

Question 31

the viral genes _______ and _______, encoded by the integrated virus, are needed to produce new retroviral particles: _______ encodes reverse transcriptase

Answer 31

gag
env
pol

Question 32

Many types of _______ are found in yeast; these can cause insertional mutations

Answer 32

ty retrotransposons

Question 33

multiple forms of _______ elements are found in the drosophilia genome

Answer 33

copia

Question 34

_______ and _______ are relatively abundant and can cause mutation in humans

Answer 34

Long Interspersed elements (LINEs)
Short Interspersed elements (SINEs)

Question 35

_______ are particularly common LINEs

Answer 35

L1 Elements

Question 36

_______ are the most common of the SINEs and actively generate mutation

Answer 36

Alu Elements