Mutations

Question 1

What are mutations

Answer 1

Mutations are changes in the DNA that can result in no protein or an altered protein being synthesised

Question 2

What is a single gene mutation

Answer 2

Single gene mutations involve the alteration of a DNA nucleotide sequence as a result of the substitution, insertion or deletion of nucleotides

Question 3

Substitution mutation

Answer 3

A substitution mutation occurs when one base is substituted for another. Substitution results in a change that only affects one codon.

Question 4

Missense mutation

Answer 4

Missense mutations results in one amino acid being changed for another. This may result in a non functional protein or have little effect on the protein.

Question 5

Nonsense substitution mutation

Answer 5

Nonsense mutations result in a premature stop codon being produced which results in a shorter protein

Question 6

Splice site (substitution) mutation

Answer 6

If there is a substitution mutation then some introns may be retained and/or some exons may not be included in the mature transcript

Question 7

Frame shift mutations

Answer 7

Cause all of the codons and all of the amino acids after the mutation to be changed. This has a major effect on the structure of the protein produced

Question 8

Frame shift mutations tend

Answer 8

To be more detrimental than substitution mutations.

Question 9

Types of disease for substitution mutations

Answer 9

Sickle cell disease(Missense)
PKU(Missense)

Question 10

Types of disease for frame shift mutations

Answer 10

Tay-sachs disease(frame shift insertion)
Cystic fibrosis(frame shift deletion)

Question 11

Deletion

Answer 11

When deletion mutation occurs, one ( or several) bases are deleted from the DNA molecule.

Question 12

Insertion

Answer 12

When insertion mutations occur, one (or several bases) are added into the DNA molecule