9.1 Gene mutation

Question 1

What is a mutation

Answer 1

Any change to the quantity or the base sequence of the DNA of an organism

Question 2

What is a gene mutation

Answer 2

Any change to one or more nucleotide bases, or a change in the sequence of bases, in DNA

Question 3

What happens when substitution of bases occurs

Answer 3

A nucleotide in a DNA molecule is replaced by another nucleotide that has a different base

Question 4

What happens when deletion of a base occurs

Answer 4

A base is lost from a normal DNA sequence. Causes a frame shift LEFT

Question 5

What is a chromosome mutation

Answer 5

A change in the structure or number of whole chromosomes

Question 6

What are the two forms of chromosome mutation

Answer 6

1. Changes in whole sets of chromosomes, may have 3 or more sets rather than the usual 2
2. Changes in the number of individual chromosomes, sometimes individual homologous pairs fail to separate during meiosis.