Genetic Recombinaton Flashcards Preview

Microbiology > Genetic Recombinaton > Flashcards

Flashcards in Genetic Recombinaton Deck (13)
1

3 pathways of genetic recombination

1. transformation
2. transduction
3. conjugation

2

transformation

uptake of plasmid or nucleoid DNA from environment

3

natural transformation

Griffith
S form has capsule; disease causing; virulent
R form does not have capsule
S form releases transforming factor (DNA) into environment
R form takes up DNA with capsule gene and is transformed into S form

4

artificial transformation

used for research

5

transduction

bacteriophage virus transfers viral and/or bacterial DNA from 1 host cell to another

6

2 forms of transduction

1. generalized
2. specialized

7

generalized transduction

virus invades host
lytic cycle

8

lytic cycle

viral reproduction destroys host

9

specialized transduction

lysogenic cycle

10

lysogenic cycle

viral DNA (with toxin) inserts in to host DNA, host lives
virus replicates with host DNA, all new cells contain virus
virus eventually reenters lytic cycle and kills host

11

conjugation

Lederburg and Tatum
plasmid DNA transferred directly between mating types
F cell and Hfr cell

12

F cell

contains fertility plasmid
functions as sex factor and forms pious
recipient cell becomes F cell and can now donate F plasmid to other cells

13

Hfr cell

high frequency of recombination
plasmid inserts into nucleoid and replicated
recipient cell not converted to Hfr