DNA damage and mutation

Question 1

DNA damage

Answer 1

a change to the regular chemical structure of the DNA double helix

Question 2

Mutation

Answer 2

a permanent heritable change in the sequence of an organism genome

Question 3

What are the different types of mutation?

Answer 3

~ point
~ chromosome
~ changes in chromosome number
~ transposon insertion

Question 4

Forward mutation

Answer 4

wild type ‘active’ to mutant ‘defective’

Question 5

Reverse mutation

Answer 5

mutant ‘defective’ to wild type ‘active’

Question 6

True reversion

Answer 6

restores sequence code for the wild type amino acid in affected protein

Question 7

Partial reversion

Answer 7

changes sequence at site of original mutation to some other aa that fully or partially restores protein function

Question 8

Suppressor mutation

Answer 8

changes sequences at a different location from original mutation but in a way that compensates for original mutation
e.g. intragenic (within same gene) and intergenic (diff genes = interacting proteins) suppressors

Question 9

Spontaneous mutation

Answer 9

arise without exposure to exogenous agents

Question 10

Random mutation

Answer 10

changes that happen by chance

~ sometimes happen to be adaptive

Question 11

Adaptive mutation

Answer 11

organisms ‘direct’ mutations to adapt to a particular environment

Question 12

Does T1 phage resistance support the adaptive or random mutation theory?

Answer 12

both

Question 13

What are the different types of mutagens?

Answer 13

chemical:
1) base analogs
2) base modifying agents
3) intercalating agents
Physical:
1) ionising radiation
2) Ultraviolet

Question 14

Transposon

Answer 14

a.k.a. a transposable element

is a DNA sequence that can change its position within a genome

Question 15

Transversion mutation

Answer 15

CG to GC

Question 16

Transition mutation

Answer 16

AT to GC

Question 17

Missense mutation

Answer 17

changes from one amino acid to another

Question 18

Nonsense mutation

Answer 18

changes from an amino acid to a stop codon (TAA, TAU, TGA)

Question 19

Neutal mutation

Answer 19

change one amino acid to another with similar chemical properties

Question 20

Silent

Answer 20

change in codon but same amino acid is specified

Question 21

Name the 7 types of point mutation.

Answer 21

Transition, transversion, missense, nonsense, neutral, silent and frameshift

Question 22

Difference between endogenous and exogenous damage?

Answer 22

endogenous = spontaneous
exogenic = environmental