Recombination & Transposition at molecular level

Question 0

what are the three main types of genetic recombination?

Answer 0

homologous recombination
site-specific recombination
transposition

Question 1

involves chromosomes breaking and rejoining to form new combinations

Answer 1

genetic recombination

Question 2

exchange of similar or identical segments of DNA

-crossing over (meiosis I and occasionally in mitosis)

Answer 2

homologous recombination

Question 3

Sister chromatid exchange does not create new combination of ____________.

Answer 3

alleles

Question 4

who (2 people) used BrdU to visualize sister chromatid exchange?

Answer 4

paul perry

sheldon wolff

Question 5

homologous chromosomes may lead to _________ ___________: the shuffling of genetic material to create new genetic combination

Answer 5

genetic recombination

Question 6

1. Holliday Model (1964): Robin Holliday

_________ ____________: the phenomenon of one allele being converted to the allele on the homologous chromosome

Answer 6

gene conversion

Question 7

in the Holliday Model of recombination, homologous chromatids are nicked at …?

Answer 7

identical locations

Question 8

__________ ___________ is formed between two chromatids

Answer 8

holliday junction

Question 9

Holliday model of recombination: branch migration can produce a ____________ (a region in double stranded DNA that contains base miss match)

Answer 9

heteroduplex

Question 10

are produced if breakage occurs on same two DNA strands originally nicked

Answer 10

nonrecombinant chromosomes

Question 11

are produced if breakage occurs in strands nor originally nicked

Answer 11

recombinant chromosomes

Question 12

more recent recombination models:

1. ___________ nick in one DNA strand initiates recombination (1975)
2. Double-stranded break model: event that initiates _______________ is the double stranded break in one of the double helixes.

Answer 12

single

recombination

Question 13

_________ are necessary to facilitate homologous recombination; different ________ catalyze different steps during recombination.

Answer 13

proteins

Question 14

when an allele is converted to the allele on the homologous chromosome.

Answer 14

gene conversion

Question 15

how does gene conversion occur?

Answer 15

1. DNA mismatch repair

2. DNA gap repair

Question 16

short DNA sequences ~12 nucleotides providing specific locations where recombination will occur.
–enzymes are needed to catalyze the ________ and __________ of DNA fragments.

Answer 16

site-specific recombination

breakage and rejoining

Question 17

can involve site-specific recombination….

Answer 17

integration of viral genomes

Question 18

__________ recognize foreign material, antigen, and target them for destruction.

Answer 18

antibodies

Question 19

site-specific recombination is used to create variation in the amino acid sequence of ___________
–this allows antibodies to recognize different antigens

Answer 19

antibodies

Question 20

whos known for transposition

-corn kernel phenotype

Answer 20

Barbara McClintock (1950s)

Question 21

DNA segments that transpose themselves around the genome

Answer 21

transposable elements

Question 22

three types of transposable pathways:

Answer 22

simple transposition
replicative transposition
retrotransposition

Question 23

element is transcribed into RNA and used as a template to synthesize a DNA molecule that is integrated into a new region.

Answer 23

retrotransposition

Question 24

transposable elements DNA sequences | -each type of TE has a characteristic pattern of DNA sequence

Answer 24

direct repeats inverted repeats long terminal repeats

Question 25

TE that contains all info needed to transposition to take place

Answer 25

autonomous elements

Question 26

TE that lacks a gene necessary for transposition

Answer 26

nonautonomous elements

Question 27

catalyzes the removal and insertion of transposons

Answer 27

transposase

Question 28

uses RNA as a template to synthesize a double stranded DNA molecule

Answer 28

reverse transcriptase

Question 29

catalyzes the insertion of the DNA into the target chromosomal DNA

Answer 29

integrase

Question 30

influences on mutation and evolution

Answer 30

- some highly/moderately repetitive sequences found in the genome are due to TE's - long interspersed elements (LINEs) - short interspersed elements (SINEs)

Question 31

TE's exist because they contain characteristics that allow them to multiply in the chromosomal DNA of living cells

Answer 31

selfish DNA hypothesis

Question 32

insertion of exons from one gene into another producing new genes with novel functions

Answer 32

exon shuffling

Question 33

when a transpoon "hops" into a gene, the genes function is likely to be inactivated

Answer 33

insertional mutagenesis

Question 34

uses an insertional mutagenesis to clone a particular gene

Answer 34

transposon tagging