gene mutation

Question 1

define mutation

Answer 1

change in quantity or structure of DNA in an organism

Question 2

define gene mutation

Answer 2

change or rearrangement of nucleotide bases in DNA

Question 3

what are the 6 types of gene mutation

Answer 3

base substitution

base addition

base inversion

base deletion

base duplication

base translocation

Question 4

what 3 types of gene mutation can be described as frame shift

Answer 4

• base addition
• base deletion
• base duplication

Question 5

what can be the 3 effects of a base subsitution

Answer 5

1. stop codon is formed and the polypeptide is not complete
2. codon for a different amino acid is formed
3. codon for the same amino acid is formed

Question 6

what are the effects of a base addition

Answer 6

• frame shift to the right
• alters whole sequence of amino acids
  primary, secondary, tertiary structure of protein changed
  structure and function of a protein changed

high chance of changing phenotype

Question 7

what are the effects of a base inversion

Answer 7

• affects amino acid sequence at this part but not before or after
• codon different = different amino acid
• codon same = same amino acid
• stop codon

Question 8

what are the effects of a base deletion

Answer 8

• frame shift to the left
• alters whole sequence of amino acids
• primary, secondary, tertiary structure changed
• change in function and shape

HIGH chance of changing phenotype

Question 9

what are the effects of a base duplication

Answer 9

• frame shift to the right
• alters whole sequence of amino acids
  different primary, secondary, tertiary structure
• different shape and function

HIGH chance of changing phenotype

Question 10

what is the mechanism for a base translocation

Answer 10

sequence of bases separated from DNA on one chromosome and added to DNA of a different chromosome

Question 11

what are the effects of a base translocation

Answer 11

significant effect on gene expression leading to abnormal phenotype

Question 12

describe 3 causes of mutation (3 marks)

Answer 12

• arise spontaneously during DNA replication
• high energy ionising radiation
• chemicals