1.6 Mutations

Question 1

Mutation

Answer 1

Change in an organisms’ DNA resulting in no protein or an altered protein being synthesised

Question 2

Mutation frequency

Answer 2

Spontaneous and random, but rarely

Question 3

Single gene mutations

Answer 3

Involves the alteration of a DNA nucleotides sequence

Question 4

Single gene mutation- Substitution, Insertion, Deletion

Answer 4

Substitution: A single nucleotide is replaced

Insertion: A single nucleotide is added

Deletion: A single nucleotide is removed

Question 5

Substitution- Missense

Answer 5

Changes the codon for a different amino acid, resulting in a non-functioning protein

Question 6

Substitution- Nonsense

Answer 6

Codon used to code for an amino acid is changed to a stop codon, resulting in a shorter protein

Question 7

Substitution- Splice site mutations

Answer 7

Codon for the intron or exon is affected, resulting in either intron being retained or exon being cut out

Question 8

Chromosome structure mutations

Answer 8

Alterations to the structure of a chromosome

Question 9

Chromosome structure mutations- Duplication, Deletion, Inversion, Translocation

Answer 9

Duplication: Section of chromosome is added to its homologous pair

Deletion: Section of chromosome is removed

Inversion: Section of chromosome is reversed

Translocation: Section of chromosome is added to not its homologous pair

Question 10

Importance of single gene mutations in evolution

Answer 10

Only source of new variation for selection

Most mutations are harmful but some have a selective advantage

Mutations are the raw material for evolution

Question 11

Importance of gene duplication in evolution

Answer 11

Produces a second copy of the gene which is free from selection pressure

Additional gene can become altered from mutation without affecting original genes function

Organism can still express original gene to produce original protein