Unit 1 - Mutations

Question 1

Define Mutations

Answer 1

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

Question 2

What are the two categories of Mutations

Answer 2

1. Single gene mutations​
2. Chromosome mutations

Question 3

What is aSingle gene mutation?

Answer 3

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

Question 4

What are the 3 categories of Single gene mutations?

Answer 4

1. Substitution​
2. Insertion​
3. Deletion

Question 5

Single gene Insertion and deletion mutations are classified as….

Answer 5

Frame-shift mutation​

Question 6

Substituton mutations are categorised as

(Other than single gene)

Answer 6

Point Mutations

Question 7

What are the types of substitution mutations

Answer 7

1. Missense​
2. Nonsense​
3. Splice-site

Question 8

Describe Missense mutations

Answer 8

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

This may result in a non-functional protein or have little effect on the protein ​

e.g. Sickle cell anaemia

Question 9

Describe Nonsense mutations

Answer 9

A nonsense mutation results in the​ code for an amino acid being changed to a premature stop codon. ​

This can result in an abnormally​ short protein which may not function properly.

Question 10

Describe Splice-site mutations, insertion and deletion

Answer 10

Frame-shift mutations 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 and function of the protein produced. ​

Insertion mutations involve the addition (insertion) of one or more nucleotides into a section of DNA. ​

Deletion mutations refer to the removal (deletion) of one or more nucleotides from a section of DNA.

Question 11

Between Single gene mutations and Chromosomal mutations, which is worse and why?

Answer 11

Chromosomal mutations because they are often lethal

Question 12

What are the 4 types of Chromosomal Mutations?

Answer 12

1. Translocation​
2. Inversion​
3. Deletion​
4. Duplication​

Question 13

Describe the Chromosomal Mutation Translocation

Answer 13

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

Question 14

Describe the Chromosomal Mutation Inversion

Answer 14

Inversion is where a section of chromosome is reversed.

Question 15

Describe the Chromosomal Mutation Deletion

Answer 15

Deletion is where a section of chromosome is removed

Question 16

Describe the Chromosomal Mutation Duplication

Answer 16

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