DNA Mutation And Repair

Question 1

physical agents (mutagens)

Answer 1

Ionizing radiation, ultraviolet light

Question 2

Chemical agents (mutagen)

Answer 2

Reactive Oxygen Species (ROS): peroxide, superoxide, and hydroxyl radical

Question 3

T or F. All mutagens change DNA

Answer 3

True

Question 4

T or F. Mutagens are a subtype of carcinogens

Answer 4

False. Carcinogens are a subtype of mutagens

Question 5

Mutations that occur without exposure to mutagenic agents. These often arise during DNA replication

Answer 5

Spontaneous mutations

Question 6

Mutation mechanisms

Answer 6

Substitution, insertion, deletion

Question 7

Base pair substitution 3 effects

Answer 7

Silent mutations- No change
Missense mutations- different amino acid
Nonsense mutations- stop codon

Question 8

What does it mean to say that the genetic code is degenerate

Answer 8

Multiple codons can code for the same amino acid

Question 9

The new and original amino acid have similar structures.

Answer 9

Conservative missense mutation

Question 10

The new and original amino acid have different structures

Answer 10

Nonconservative missense mutation

Question 11

What are the 3 stop codons

Answer 11

UGA, UAA, UAG

Question 12

This mutation causes the protein production to stop prematurely and therefore, truncates or shortens the protein, typically rendering it entirely nonfunctional

Answer 12

Nonsense mutation

Question 13

Insertion and deletion can have enormous impacts when this occurs?

Answer 13

Frameshift

Question 14

T or F. All insertions and deletions are frameshift mutations.

Answer 14

False, if the nucleotides added or deleted are multiple of 3, it won’t shift the frame

Question 15

Point mutations can be?

Answer 15

Substitution, insertion, or deletion

Question 16

Mutations that partially or entirely prevent a protein from functioning properly

Answer 16

Loss of function mutations

Question 17

Mutations that cause proteins to take on a new function

Answer 17

Gain of Function

Question 18

Chromosomal abnormalities include?

Answer 18

Deletion, duplication, inversion, insertion, translocation, and aneuploidy

Question 19

Which of the chromosomal abnormalities take place on a single chromosome

Answer 19

Deletion, duplication, and inversion

Question 20

T or F. Deletion in a segment of gene in one chromosome may not be detrimental if the other chromosome can compensate for this loss.

Answer 20

True

Question 21

This chromosomal abnormality does not change gene dosage and therefore, most have no noticeable effects

Answer 21

Inversion

Question 22

These 2 chromosomal abnormalities tend to effect 2 chromosomes

Answer 22

Insertion and translocation

Question 23

This is when a segment of one chromosome is exchanged with genetic material in the other.

Answer 23

Translocation

Question 24

When the translocation does not result in a loss or gain of extra genes and is typically harmless it is called?

Answer 24

Balanced translocation

Question 25

While an individual may not be affected by translocation, its child could. The child could have what kind of translocation

Answer 25

Unbalanced

Question 26

This when a segment of one chromosome transfers to the other only.

Answer 26

Insertion

Question 27

These are generally non-coding genetic elements that can initiate their own movement form chromosome to chromosome

Answer 27

Transposons

Question 28

Transposons comprise what percentage of the genome

Answer 28

40%

Question 29

T or F. Transposition is not the same as translocation as the movement is one way and no exchanging occurs

Answer 29

True

Question 30

An abnormal number of copies of chromosome in the cell

Answer 30

Aneuploidy

Question 31

This chromosomal abnormality typically results form nondisjunction

Answer 31

Aneuploidy

Question 32

T or F. The risk of aneuploidy increases with maternal age .

Answer 32

True

Question 33

The ability to proofread the growing strand is also known as

Answer 33

3’ -> 5’ exonuclease

Question 34

Occurs immediately after DNA replication and continues through the G2 stage of the cell cycle.

Answer 34

Mismatch repair

Question 35

T or F. The old strand of the DNA strand is methylated more than new strand

Answer 35

True

Question 36

T or F. Mismatch repair functions only to repair errors introduced during DNA replication

Answer 36

True

Question 37

2 repair pathways that can repair errors throughout the cell cyle

Answer 37

Base excision repair and nucleotide excision repair

Question 38

This removes one base and is this type of repair can only fix relatively small scale errors such as mismatched pairs, oxidized bases, or maybe the mistaken inclusion of uracil in DNA

Answer 38

Base excision repair

Question 39

This DNA repair can remove multiple bases, allowing it to fix larger mutations such as pyrimidine dimers

Answer 39

Nucleotide excision repair

Question 40

What can cause pyrimidine dimers

Answer 40

UV light

Question 41

What are the pyrimidine bases

Answer 41

Thymine and cytosine