20.1 Gene Mutations

Question 1

Gene mutation definition

Answer 1

Any change to one or more nucleotide bases, or any arrangement of the bases in DNA

Question 2

Substitution of bases definition

Answer 2

Nucleotide is replaced by another nucleotide that has a different base

Question 3

Deletion of bases definition

Answer 3

Loss of a nucleotide from a DNA sequence

Question 4

Addition of bases definition

Answer 4

An extra base becomes inserted in the sequence

Question 5

Duplication of bases definition

Answer 5

One or more bases are repeated

Question 6

Inversion of bases definition

Answer 6

A group of bases become separated from the DNA sequence and join at the same position but in the reverse order

Question 7

Translocation of bases definition

Answer 7

A group of bases become separated from the DNA sequence in one chromosome and become inserted into the DNA sequence of a different chromosome

Question 8

What are mutagenic agents?

Answer 8

Outside factors that can increase the rate of mutation

Question 9

Examples of mutagenic agents

Answer 9

• high energy ionising radiation

- chemicals (NO2)