Genetics

Question 1

Errors in translation effect how many proteins?

Answer 1

1

Question 2

Errors in transcription affect how many proteins?

Answer 2

affect a subset of proteins translated from the transcript with error

Question 3

Mutations affect how many proteins?

Answer 3

ALL proteins encoded by that gene and ALL descendants of that mutant strain

Question 4

Where do mutations arise?

Answer 4

During replication

Question 5

What is the primary replicating polymerase?

Answer 5

DNA poly III

Question 6

what are mutagens?

Answer 6

environmental factors that damage DNA

Question 7

Benzopyrene mutagen, what does it do

Answer 7

dsDNA intercalating agents disort double helix

Question 8

methyl-nitrosoguanidine mutagen, what does it do

Answer 8

chemical modification of base

Question 9

UV light mutagen, what does it do?

Answer 9

base crosslinking

Question 10

ionizing radiation mutagen, what does it do

Answer 10

base elimination

Question 11

is a mutation heritable?

Answer 11

Yes.

Question 12

What is a genotype

Answer 12

DNA sequence of a gene/chromosome

Question 13

What is a phenotype

Answer 13

measurable/observable trait conferred by a gene, mediated by proteins

Question 14

What is an allele

Answer 14

a version of gene

Question 15

a random mutation will almost always result in protein what?

Answer 15

loss of function

Question 16

very very rarely a what will arise that increases or changes protein activity

Answer 16

gain-of-function

Question 17

Missense mutation

Answer 17

single base pair change that changes the codon to a different amino acid

Question 18

nonsense mutation

Answer 18

single base pair that changes the codon to a premature stop codon

Question 19

silent mutation

Answer 19

changes the codon but codes for the same amino acid due to degeneracy

Question 20

frameshift mutation

Answer 20

insertion or deletion of base paris in amounts not divisible by 3. completley alter subsequent amino acid sequence

Question 21

Polarity

Answer 21

side effect of mutations within operons

Question 22

Order of how frequent

Answer 22

1. mutagen
2. slipped strand mispairing
3. missense loss of function
4. missense gain of function

Question 23

How does DNA pol III repair a mismatch

Answer 23

exonnuclease activity, backs up one base and excises it

Question 24

methyl - directed mismatch repair

Answer 24

repairs mismatch pairs

Question 25

MutS

Answer 25

recognizes and binds to DNA distortion

Question 26

MutL

Answer 26

“linker protein” recruits MutH to MutS

Question 27

MutH

Answer 27

endonuclease, nicks DNA near damaged base

Question 28

DNA polymerase I

Answer 28

repair polymerase, loads and fills in gap after methyl-directed mismatch repair

Question 29

how does MutHSL recognize which is damaged strand?

Answer 29

newer strands lack methyl groups, so cut out distortion on un-methylated DNA strand

Question 30

DNA methyltransferase (DNA MTase)

Answer 30

methylates DNA after replication

Question 31

how are mismatches repaired after replication like when a mutagen chemically damages a base?

Answer 31

cell activates SOS system

Question 32

RecA protein

Answer 32

in SOS system, binds to damaged base and becomes activated to RecA*

Question 33

LexA

Answer 33

transcriptional repressor DNA binding protein that inhibits SOS genes

Question 34

RecA*

Answer 34

cleaves LexA and de-represses SOS genes

Question 35

SOS genes (3)

Answer 35

SulA–inhibitor of FtsZ
UvrABC- DNA excision repair
Pol IV– error prone polymerase

Question 36

SulA

Answer 36

interacts with FtsZ and blocks z-ring formation until DNA damage has been resolved

Question 37

UvrABC

Answer 37

can excise damaged nucleotides

Question 38

DNA poly IV

Answer 38

copies over the top of damaged nucleotides, prone to error