Mutations

Question 1

what do gene mutations involve?

Answer 1

a change in the DNA base sequences of chromosomes

Question 2

what are the errors that can occur?

Answer 2

• substitution
• deletion

Question 3

what is substitution?

Answer 3

where one base is substituted for another in the DNA base sequence

Question 4

what is deletion?

Answer 4

where one base is deleted in the DNA base sequence

Question 5

what affect do substitutions have on the sequence?

Answer 5

they don’t always lead to changes within the amino acid sequence as the code is degenerate, so more than one triplet can code for the correct amino acid

Question 6

what affect do deletions have on the sequence?

Answer 6

they change the number of bases present, causing a shift in all the bases after, altering every triplet, always leading to changes within the amino acid sequence

Question 7

what are mutagenic agents?

Answer 7

agents/ things that increase the rate of mutations

Question 8

list examples of mutagenic agents

Answer 8

• UV radiation
• ionising radiation
• some chemicals
• some viruses