Mutations - 1.6

Question 1

What is a mutation?

Answer 1

changes in DNA that can result in no protein, or altered protein being synthesised

Question 2

What are the three types of single gene mutation ?

Answer 2

substitution, deletion, insertion

Question 3

What is a substitution mutation?

Answer 3

a single nucleotide is removed from the DNA sequence and replaced with another

Question 4

What are the three types of substitution mutations?

Answer 4

missense
nonsense
splice - site

Question 5

What happens in a missense mutation

Answer 5

result in one amino acid being swapped from another , non functional protein or little effect

Question 6

What happens in a nonsense mutation

Answer 6

a codon that is used to code for an amino acid is swapped for a stop codon

Question 7

What happens in a splice site insertion

Answer 7

extra nucleotide is added into sequence

Question 8

what happens in a splice site deletion

Answer 8

nucleotide is removed from sequence

Question 9

What are the four types of chromosome structure mutation

Answer 9

deletion, duplication, inversion, translocation

Question 10

Single genes - extended response

Answer 10

• mutations are random changes in DNA sequences
• *substitution - nucleotide is replaced by another
  *insertion - nucleotide is added to the sequence
  *deletion - nucleotide is removed
  -insertion results in a frame shift mutation
  -single nucleotide substitutions are missense, nonsense, splice site

Question 11

Chromosome structure mutations - extended response

Answer 11

• deletion is where a section of a chromosome is removed
  -duplication is when a section of a chromosome is added to its homologous partner
  -translocation is when a section of a chromosome is added to its non-homologous partner
  -inversion is where a section of the chromosome is reversed