Mutation - Lecture 1

Question 1

What is the difference between somatic and germline mutations?

Answer 1

somatic - occurs in somatic cells that do not undergo meiosis
Germline- occurs in gremlin cells. that pass mutation onto progeny

Question 2

What are the main types of point mutations?

Answer 2

base substitution, frameshift mutation, and tautomeric shift

Question 3

What is a base substitution mutation?

Answer 3

Transition mutation - pyrimidine is replaced with another pyrimidine or a purine is replaced with another purine
transversion mutation - pyrimidine is replaced with a purine or a purine is replaced with a pyrimidine

Question 4

What is a frameshift mutation?

Answer 4

occurs when a base that is not a multiple of 3 is inserted or deleted from a gene

Question 5

What is a tautomeric shift?

Answer 5

when bases change to their tautomeric form and can generate A:C and G:T base pairs resulting in a transition mutation

Question 6

What is an expanding nucleotide repeat mutation?

Answer 6

when a DNA molecule has several repeats of a codon and this DNA is replicated but during replication a hairpin structure forms and the resulting DNA molecule has even more codon repeats

Question 7

What is the difference between a forward and reverse mutation?

Answer 7

forward mutation changes to wild type to mutant and a reverse mutation changes the mutant to the wild type

Question 8

What is a missense mutation?

Answer 8

a base substitution that results in an AA change in the protein

Question 9

What is a nonsense mutation?

Answer 9

a base substitution that changes the sense codon to a stop codon

Question 10

What is a silent mutation?

Answer 10

a base substitution at the 3rd codon position that changes the codon but still encodes for the same AA

Question 11

What is a neutral mutation?

Answer 11

a missense mutation in which the AA is changed to one of a similar chemical type

Question 12

What is a loss-of-function mutation?

Answer 12

the result of a mutation that causes complete or partial loos of function in the protein

Question 13

What is a gain-of-function mutation?

Answer 13

the result of a mutation that causes the cell to produce a protein with an additional function

Question 14

What is a conditional mutation?

Answer 14

A mutation that only is expressed under certain conditions

Question 15

What is a lethal mutation?

Answer 15

causes premature death