1.6 - Mutations

Question 1

Mutations

Answer 1

Mutations are random changes in DNA that can result in no protein or an altered protein being produced.

Question 2

Single Gene Mutations

Answer 2

Single gene mutation involves the changing of a DNA nucleotide sequence.

Question 3

Insertion

Answer 3

Insertion involves the addition of a nucleotide.

Insertion is a frameshift mutation.

Question 4

Deletion

Answer 4

Deletion involves the removal of a nucleotide.

Deletion is a frameshift mutation

Question 5

Frameshift Mutation

Answer 5

This means that the sequence of every amino acid after the mutation will cause every codon to be different. This will mean that every amino acid will be different so the protein will either not work or be different.

Question 6

Substitution

Answer 6

Substitution involves the replacing of a nucleotide.

This means only one amino acid is affected. There are different effects that a substitution mutation can have on a protein.

Question 7

Types of Substitution Mutation: Missense

Answer 7

Result in one amino acid being changed for another. This may have little effect on the final protein or may change the protein to make it non-functional.

Question 8

Types of Substitution Mutation: Nonsense

Answer 8

Result in a premature stop codon being produced. This results in a smaller protein which will be non-functional.

Question 9

Types of Substitution Mutation: Splice-site

Answer 9

Result in some introns being kept in the mature transcript OR some exons being removed from the mature transcript.

Question 10

Chromosome Structure Mutations

Answer 10

Chromosome structure mutations involve the changing of a section of a chromosome.
Substantial changes in chromosomes from mutations often make them lethal.

Question 11

Chromosome Structure Mutations: Deletion

Answer 11

When a section of a chromosome is removed.

Question 12

Chromosome Structure Mutations: Inversion

Answer 12

When a section of a chromosome is reversed.

Question 13

Chromosome Structure Mutations: Translocation

Answer 13

A section of a chromosome is attached to another chromosome that is not its homologous partner (matching chromosome)

Question 14

Chromosome Structure Mutations: Duplication

Answer 14

Where a section of a chromosome is added from its homologous partner (matching chromosome)

Question 15

Evolutionary Importance of Gene Duplication

Answer 15

Duplication of a gene produces a second copy that is free from selections pressures so the organism can mutate to produce new DNA sequences.

This is advantageous because it allows potential beneficial mutations to occur in a duplicated gene while the original gene can still be expressed to produce its protein.