block a lec 2

Question 1

what is HGT

Answer 1

the transfer of genes from one independent organism to another

Question 2

what do stable recombinants have

Answer 2

characteristics of donor and recipient

Question 3

why is HGT important

Answer 3

expansion of ecological niche, increased survival

Question 4

3 methods in which DNA can be donated

Answer 4

conjugation
transformation
transduction

Question 5

what are 2 stable recombinant fates

Answer 5

integration of donor DNA (occurs in organisms that are genetically close)
donor DNA self replicates

Question 6

2 unstable recombinant fates

Answer 6

diluted down if donor DNA cannot self replicate
host restriction degrades foreign DNA

Question 7

what is transformation

Answer 7

genetic transfer process by which DNA is incorporated into a recipient cell and brings about genetic change

Question 8

what does competent mean

Answer 8

cells are capable of taking up (naked) DNA and being transformed

Question 9

name given to process where electricity is used to force cells to take up DNA

Answer 9

electroporation

Question 10

what is competence said to be in naturally transformable bacteria

Answer 10

regulated

Question 11

what is transfection

Answer 11

transformation of bacteria with DNA extracted from a bacterial virus

Question 12

how is transfection carried out

Answer 12

integration or replication of the bacteriophage

Question 13

what is transduction

Answer 13

transfer of DNA from one cell to another by a bacteriophage due to mispackaging of the bacteriophage genome

Question 14

what are the names of the 2 modes of transduction

Answer 14

generalised and specialised

Question 15

what is generalised transduction

Answer 15

DNA from any part of the host genome is packaged inside the virion

Question 16

what is specialised transduction

Answer 16

DNA from a specific region of the host chr is integrated directly into the virus genome

Question 17

what do phage heads have

Answer 17

a discrete amount of DNA that they can take

Question 18

what is the most abundant phage on the planet

Answer 18

bacteriophage

Question 19

generalised transduction efficiency

Answer 19

low

Question 20

what step does temperate generalised transduction have

Answer 20

lysogeny

Question 21

what step does virulent generalised transduction have

Answer 21

lytic

Question 22

efficiency of specialised transduction

Answer 22

can be high

Question 23

how does transfer of genes work in s temperate pecialised transduction

Answer 23

DNA of temperate virus excises incorrectly and takes adjacent host genes along with it

Question 24

what is phage conversion

Answer 24

alteration of the phenotype of a host cell by lysogenisation

Question 25

what happens when a non defective temperate phage lysogenises a cell

Answer 25

becomes a prophage

Question 26

what is homoimmunity

Answer 26

when a host cell becomes immune to further infection by same phage

Question 27

what can the genome of prophages encode

Answer 27

things that are beneficial to the host

Question 28

what is bacterial conjugation

Answer 28

mating mechanism of genetic transfer that involves cell to cell contact

Question 29

what is the difference in plasmids in conjugated donor and recipient cell

Answer 29

donor cell contains conjugative plasmid recipient cell does not contain plasmid

Question 30

what does F plasmid contain

Answer 30

genes that regulate DNA rep several transposable elements that allow host chr integration

Question 31

what are insertion elements

Answer 31

they integrate and excise, hop around genes

Question 32

what is essential for conjugation

Answer 32

sex pilus

Question 33

what are finbry

Answer 33

short protonation receptors

Question 34

how is DNA synthesised in conjugation

Answer 34

rolling circle replication

Question 35

what is it called when a cell has a non integrated F plasmid

Answer 35

F+

Question 36

what are cells that have an integrated F plasmid called

Answer 36

Hfr high frequency of recombination

Question 37

what can F plasmid integrate into

Answer 37

host chr

Question 38

what does presence of F plasmid result in

Answer 38

alterations in cell properties

Question 39

what do insertion sequences do

Answer 39

facilitate homologous recombination

Question 40

what if only a portion of integrated F plasmid is transferred by donor

Answer 40

recipient cell does not become Hfr

Question 41

what happens if Hfr strains differ in integration position of F plasmid

Answer 41

transfer genes in diff order

Question 42

what are genetic crosses used for

Answer 42

with HFr strains to map order of genes on chr

Question 43

what are F' plasmids

Answer 43

previously integrated F plasmids that have excised and captured some chr genes