Topic 8 - 2 - Mutagenic Agents

Question 1

What is a mutagenic agent?

Answer 1

Something that increases the rate of DNA mutations

Question 2

Give one example of a mutagenic agent

Answer 2

Ultraviolet Radiation
Ionising Radiation
Chemicals
Viruses

Question 3

What are three ways mutagenic agents increase the rate of mutations

Answer 3

1 - Acting as a base (Substitution)
2- Altering bases (Deletion)
3 - Changing the structure of DNA (Causes problems during DNA
replication)

Question 4

Give an example of how mutagenic agents increase the rate of mutations by substitution

Answer 4

5-Bromouracil is a base analogue that can substitute for thymine. It can pair with guanine (instead of adenine) causing a substitution mutation in the new DNA.

Question 5

Give an example of how mutagenic agents increase the rate of mutations by deletion, or altering bases

Answer 5

Alkylating agents can add an alkyl group to guanine, which changes the structure so that it pairs with thymine (instead of cytosine)

Question 6

Give an example of how mutagenic agents increase the rate of mutations by Changing the structure of DNA

Answer 6

UV radiation can cause adjacent thymine bases to pair up together