Mutations

Question 1

What is a mutation?

Answer 1

an alteration to the DNA base sequence

Question 2

Why might a mutation not lead to a change in the amino acid sequence?

Answer 2

• Genetic code is degenerate, so may code for the same amino acid
• may change an intron which is not expressed

Question 3

What is a substitution mutation?

Answer 3

When a nucleotide in the base sequence is replaced by another (more likely not to change the a/a sequnce)

Question 4

What is a deletion mutation?

Answer 4

When a nucleotide in the DNA sequence is removed/lost.

Question 5

What is a frame shift mutation?

Answer 5

the mutation results in the rest of the base sequence being impacted, therefore causing a greater impact of the codons and therefore the amino acid sequence that is coded for.

Question 6

What is a mutagenic agent?

Answer 6

a factor that increases the risk of mutations

Question 7

What is a polyploidy mutation?

Answer 7

where there are 3 or more copies of a chromosome present

Question 8

What is chromosome non-disjunction?

Answer 8

when chromosomes fail to separate properly in meiosis