Mutations

Question 1

What senses nutrient deprivation for endospore formation

what initiates endospore formation

Answer 1

Sensor Kinase A

kinase cascade

activates sigma factors

Question 2

Activation of sigma factors in endospores….

Answer 2

sigma F early sporulation

sigma G late sporulation

Question 3

Endospore formation has two things. They are

Answer 3

spatial recognition (dif. sigma factors recognize different parts)

timing (activation of these sigma factors is dependent on kinase pathway)

Question 4

endospore formation is due to

Answer 4

changes in gene expression

Question 5

silent mutation

Answer 5

single base substitution that doesn’t cause a change in expression (usually third)

Question 6

missesne mutation

Answer 6

single base substitution that causes expression of different AA

Question 7

nonsense mutation

Answer 7

point mutation in a sequence of DNA that results in a premature stop codon

Question 8

frameshift mutation

Answer 8

insertion/deletion of a number of nucleotides

Question 9

forward mutation is followed by a

Answer 9

reversion follows

Question 10

reversion mutations are utilized for

Answer 10

Ames test

Question 11

Ames test

Answer 11

test for carcinogens

checking to see if carcinogenic because it causes increase in reversion (something that is already mutated)

Question 12

genetic variation is caused by which 2 mechanisms

Answer 12

mutation
horizontal gene transfer

these can also lead to antibiotic resistance

Question 13

3 mechanisms of horizontal gene transfer

Answer 13

conjugation
transformation
transduction

Question 14

3 types of conjugation

Answer 14

F+ x F-
Hfr
F’

Question 15

Hfr conjugation

Answer 15

F factor is integrated to chromosome

recombinant cells are found in a high frequency

F+ cell integrates into genome which then transfer genes from genome

Question 16

recipient cells during Hfr, do they become F+?

Answer 16

NO

they are incapable of horizontal gene transfer

Question 17

results of Hfr

Answer 17

2 F factor

piece of genome from donor cell that can undergo recombination

requires new phenotype but can’t horizontally donate to new cell

Question 18

integrated into genome – what type of conjugation

Answer 18

Hfr

Question 19

F’

Answer 19

F factor is excised out

transfer of F factor results in transfer of other genes that have been excised

Question 20

which conjugation can only transfer what is excised out (F’ no longer associated with genome)

Answer 20

F’

No longer integrated in genome

Question 21

F+ x F-

Answer 21

transfer of genes from F+ to F-

will have add-on basically of F plasmid

Question 22

lytic phages do which type of transduction?

Answer 22

generalized transduction

Question 23

what are the 2 types of transduction?

Answer 23

generalized and specialized

Question 24

generalized transduction

Answer 24

phage breaks up during infection portion,

error in patching results in phage with part of e.coli cell genome

transferred to recipient cell

incorporated into genome

Question 25

generalized transduction (general characteristics)

Answer 25

don’t generate more phages

2 phage system (one infects, one picks up some from donor cell DNA)

Question 26

specialized transduction

Answer 26

carried out by temperate phages

must have lysogeny

Question 27

steps in specialized transduction

Answer 27

lysogenized phage that has prophage

stimulated to turn on

rarely, but possible, but it pulls out some of host genes

when packaged it is carried on and infects immune cells