Mutation and Genetic Diseases

Question 1

Definition of mutation

Answer 1

The change in the structure of a gene or chromosome number

Question 2

What happens if there is a change in the structure of a gene?

Answer 2

A change in the structure of a gene may result in a change in the sequence of codons, resulting in a change in the sequence of amino acids of the polypeptide, hence forming a different protein as the polypeptide folds differently

Question 3

Factors increasing the rate of mutation

Answer 3

1. Exposure to ionising radiation (e.g UV radiation and X-ray radiation)
2. Exposure to chemical mutagens (e.g tar in tobacco smoke)

Question 4

Sickle cell anaemia

Answer 4

Condition caused by a mutation involving the change in the structure of the haemoglobin gene

Question 5

Down’s syndrome

Answer 5

Condition caused by a mutation involving a change in the number of chromosomes
- an individual has an extra copy of chromosome 21. Therefore, the individual has 47 chromosomes