genetic recombination

Question 1

dna recombination mechanisms

Answer 1

-homogous recombination
-conjugation
-transformation
-transduction
-site-specific recombination

Question 2

occurs between identical or nearly identical sequences, also called general recombination

Answer 2

homologous recombination

Question 3

cuts the holliday junction vertically or horizontally

Answer 3

endonuclease (ruvC)

Question 4

-crossover products
-rearrangement of genetic material around the site of recombination

Answer 4

splice products

Question 5

transmission of genetic information from donor bacterium to a recipient cell

Answer 5

bacterial conjugation

Question 6

introduction of an exogenous dna into a cell, causing the cell to acquire a new phenotype

Answer 6

transformation

Question 7

4 steps of transformation

Answer 7

1. a donor bacterium dies and is degraded
2. a fragment of DNA from the dead donor binds to DNA binding proteins on the cell wall of a living recipient bacterium
3. the Rec A protein promotes genetic exchange between a fragment of the donor’s DNA and the recipient DNA.
4. exchange is complete

Question 8

transfer of dna fragments from one bacterium to another bacterium by a bacteriophage

Answer 8

transduction

Question 9

obligate intracellular parasites that multiply inside bacteria by making use of the host biosynthetic machinery

Answer 9

bacteriophage

Question 10

2 types of transduction

Answer 10

-generalized
-specialized

Question 11

7 steps in generalized transduction

Answer 11

1.a lytic bacteriophage attaches to a bacterium
2.genome enters the bacterium and manufacture bacteriophage components
3.dna from host bacterium may enter among the new bacteriophage
4.bacteriophages are released
5.bacteriophage carrying the donor’s dna attaches to another bacterium
6.bacteriophage inserts the donor’s dna into the recipient bacterium
7.donor bacterium’s dna is exchanged for some of the recipient’s dna.

Question 12

4 steps of sepcialised transduction

Answer 12

1. a bacteriophage attaches to a bacterium and injects its genome
2. genome is inserted into the nucleoid to become a prophage
3. a small piece of the donor’s dna is picked up as part of the phage’s genome
4. bacteriophage replicates and every phage now carries that segment of bacterial dna.

Question 13

-occurs at a specific dna sequence

Answer 13

site-specific recombination

Question 14

-transposable genetic element
-piece of dna that can move from one location to another in cell’s genome

Answer 14

transposons

Question 15

3 mechanisms of transposition

Answer 15

-conservative
-replicative
-retrotransposition

Question 16

conservative transposition

Answer 16

-directly transfers itself from the donor site into the target site

Question 17

replicative transposition

Answer 17

makes a copy of itself into a new site

Question 18

retrotransposition

Answer 18

makes an rna copy of itself which is reverse-transcribed into a dna copy which is then inserted (cDNA)