Part C: Lecture 9

Question 1

Mutation is both ______in the DNA and the
process by which _____

Answer 1

-a heritable change (outcome)
-such a change occurs (event)

Question 2

Mutant (def.)

Answer 2

a cell/organism carrying a mutation

Question 3

Two types of mutations

Answer 3

-spontaneous
-induced

Question 4

Spontaneous mutations are ____

Answer 4

accidental

Question 5

Induced mutations are due to _____

Answer 5

external factor

Question 6

Mutagen (def.)

Answer 6

a physical or chemical agent that raises the frequency of mutation above the spontaneous rate

Question 7

Even without mutagens, a certain number of ____ will still occur

Answer 7

mutations

Question 8

DNA lesion is ____

Answer 8

physical damage to DNA

Question 9

3 results of DNA lesions

Answer 9

-kills cells
-repaired correctly
-repaired wrong

Question 10

Process of mutation

Answer 10

1) DNA lesion
2) no/incorrect repair

Question 11

Deamination of cytosine is a ____

Answer 11

spontaneous reaction that turns cytosine -> uracil

Question 12

Deamination of cytosine process

Answer 12

cytosine + H20 -> NH3 + uracil
(lose amine group, replace with O from H2O)

Question 13

How common is deamination of cytosine

Answer 13

100 bases/cell/day

Question 14

Immediate result of deamination of cytosine

Answer 14

GC -> GU

Question 15

Overall result of deamination of cytosine PROCESS

Answer 15

GC –> GU –> (after dna rep.) GC + AU –> (after dna rep.) AT + AU

Question 16

Overall result of deamination of cytosine (GC bp ->

Answer 16

AT bp

Question 17

GC -> AT is the same as saying ____

Answer 17

CG -> TA

Question 18

Base excision repair (BER) steps

Answer 18

1) DNA repair enzymes recognize defective bases and remove them
2)Other DNA repair enzymes fix AP site

Question 19

DNA repair enzymes fix ___ not ____

Answer 19

lesions not mutations

Question 20

Uracil DNA Glycosylase recognizes ___

Answer 20

uracil in DNA molecule for removal

Question 21

AP sites are ___

Answer 21

places in DNA missing a base

Question 22

Two types of AP sites

Answer 22

apurinic sites
apyrimidinic sites

Question 23

apurinic sites are missing ___

Answer 23

A or G

Question 24

apyrimidinic sites are missing ___

Answer 24

C or T

Question 25

BER of deamination of cytosine

Answer 25

1) removal of uracil base by uracil DNA glycosylase (creates AP site)
2) DNA repair enzymes remove the sugar+ phosphate backbone
3) dCTP + DNA Pol, DNA ligase repair space in DNA

Question 26

Prompt repair of lesion will ____

Answer 26

stop mutation from occurring

Question 27

Repairing DNA right after deamination of cytosine result

Answer 27

GC –> GU -> GC

Question 28

Delayed repair of lesion will cause ___

Answer 28

a mutation

Question 29

Repair of DNA right after DNA replication after deamination of cytosine

Answer 29

GC –> GU –> AT

Question 30

Repeats are ___ in chromosomes

Answer 30

common

Question 31

In human chromosomes, we have a lot of ___ repeats

Answer 31

CACA

Question 32

DNA pol falls off a repeat and the strands reanneal incorrectly so when____

Answer 32

DNA Pol returns. one strand will have more nucleotides

Question 33

If the new strand loops out, you get___

Answer 33

insertion of base pair(s)

Question 34

If template strand loops out, you get ____

Answer 34

deletion of base pair(s)

Question 35

how many types of base pair substitutions?

Answer 35

6

Question 36

types of base pair substitutions: GC ->

Answer 36

AT or TA or CG

Question 37

types of base pair substitutions: AT ->

Answer 37

GC or CG or TA

Question 38

Indels are the ____

Answer 38

insertions or deletions of 1 or more bp

Question 39

Properties of spont. mutations: Genes are more likely to mutate if they are ____

Answer 39

-are larger
-contain repeats