Chapter 16 Genetic Variation

Question 1

how does asexual reproduction limit genetic mixing?

Answer 1

• no meiosis

- no gamete fusion

Question 2

gene transfer that occures replication from parent cell to daughter cell

Answer 2

vertical gene transfer

Question 3

gene transfer that is passed from one cell to another (doesnt involve replication)

Answer 3

Horizontal gene transfer

Question 4

what are the mechanisms to aquire changes in genes for microbes?

Answer 4

• mutations

- Horizontal gene transfer between cells

Question 5

mutation caused by error in replication or spontaneous chemical change is

Answer 5

Spontaneous mutation

Question 6

mutation caused by a UV, Chemical, Radation exposure

Answer 6

Induced mutation

Question 7

list the outword effects of changing the DNA sequence all the way to the phenotype

Answer 7

1) Change in DNA
2) Change in Codon
3) Change in amino acid
4) Change in Polypeptide
5) Change in phenotype

Question 8

List possible ways of aquiring DNA in Horizontal gene(mechanisms)

Answer 8

1) conjugation
2) transformation
3) transduction

Question 9

Horizontal gene transfer mechanism:

use physical contact to transfer DNA from one cell to anothe

Answer 9

conjugation

Question 10

Horizontal gt mechanism:

pick up DNA from cell’s environment

Answer 10

Transformation

Question 11

Horizontal gt mechanism:

infection by a lysogenic bacteriophage that carries DNA from previous host

Answer 11

transduction

Question 12

in conjugation the cell produces a___ that makes connection with recipient cell.

Answer 12

pilus

Question 13

in order for conjugation to occur ___ needs to be present on the ___ plasmid

Answer 13

• transfer and mobility genes example: tra/mob

- F plasmid

Question 14

steps in conjugation (write these out)

Answer 14

1) cell makes contact with the pillus
2) the pillus shortens(making connection more stable
3) proteins form relaxisome/ bind DNA at origin of transfer
4) relaxisom cut 1 strand of DNA
5) relaxisom interacts with protein on pillus, pushing strand into opening
6) as the DNA enters the F factor DNA is replicated to form double stranded F factor.

Question 15

structure that cuts single strand on F-plasmid

Answer 15

relaxisome

Question 16

The F factor integrates with chromosome

Answer 16

high frequency of recombination (HFR)

Question 17

where does the relaxisome make contact on plasmid?

Answer 17

origin of transfer

Question 18

if the donor cell is and HFR strain is the whole chromosme likely to transfer ?

Answer 18

no

Question 19

if the donor is an HFR is the recipient lickley to gain conjugation ability?

Answer 19

no

Question 20

cells with mechanism to pick up DNA are called

Answer 20

naturally competent

Question 21

in transformation, if the bacteria picks up a whole plasmid is it likely to be a stable or unseccessful transformation

Answer 21

• stable

- because the plasmid can replicate on its own

Question 22

Bacteriophage type that infect and kill, do not transfer bacterial DNA

Answer 22

Lytic

Question 23

Bacteriophage reproductive type

-viral DNA integrates with host DNA, may carry bacterial genes

Answer 23

Temperate

Question 24

Bacteriophage reproductive cycle: viral DNA integrates with host DNA

Answer 24

Lysogenic cycle

Question 25

the major turning point that differs between the lytic and lysogenic cycle

Answer 25

• lytic cycle- goes directly to synthesising new phages

- Lysogenic cycle- viral DNA is integrated into host chromosome first

Question 26

in the lysogenic cycle,

what causes the dormant integrated viral DNA to be cut out and begin synthesis of bacterial phages (lytic cycle)

Answer 26

exposure to stress