1.6 Mutations

Question 1

What is a missense mutation?

Answer 1

A missense mutation results in one amino acid being changed for another

Question 2

What is the effect of a missense mutation?

Answer 2

A missense mutation results in a non-functional protein or has little effect on the protein

Question 3

What is a nonsense mutation?

Answer 3

Nonsense mutations result in a premature stop codon being produced

Question 4

What is the effect of a nonsense mutation?

Answer 4

Nonsense mutations result in shorter proteins being produced

Question 5

What is a splice-site mutation?

Answer 5

A splice-site mutation results in some introns being retained and/or some exons not being included in the mature transcript

Question 6

What is a frame-shift mutation?

Answer 6

Frame-shift mutations cause all of the codons and all of the amino acids after the mutation to be changed

Question 7

What is the effect of a frame-shift mutation?

Answer 7

Frame-shift mutations have a major effect on the structure of the protein.

Question 8

What is a duplication mutation?

Answer 8

Duplication is where a section of a chromosome is added from its homologous partner

Question 9

What is a deletion mutation?

Answer 9

Deletion is where a section of the chromosome is removed

Question 10

What is an inversion mutation?

Answer 10

Inversion is where a section of the chromosome is reversed

Question 11

What is a translocation mutation?

Answer 11

Translocation is where a section of a chromosome is added to a chromosome which is not its homologous partner

Question 12

Why are chromosome mutations often bad?

Answer 12

The substantial changes in chromosome mutations often make them lethal

Question 13

How is duplication important in evolution?

Answer 13

Duplication allows potential beneficial mutations to occur in the duplicated gene whilst the original gene can still be expressed to produce a protein