Topic 6 - Mutations

Question 1

Do DNA mutations always cause harm.

Answer 1

No because most mutations have little or no effect on the code genes.

Question 2

Kiera has a mutation which prevents the synthesis of enzyme X starting. Is this mutation coding or non-coding DNA?

Answer 2

Non-coding DNA

Question 3

John has a different mutation. This causes the production of a mutant form of enzyme X which can no longer break down substrate Y. Suggest how the mutation stopped the enzyme working properly. (2 marks)

Answer 3

The mutation alters the shape of the active site on the enzyme.
This means that substrate Y would not be able to fit onto the enzyme, preventing it from being broken down.