UNIT 4 (topic 3) genetic mutation

Question 1

define the term mutation

Answer 1

a permanent change to the base sequence of DNA

Question 2

what is a silent mutation

Answer 2

• one nucleotide is REPLACED with another nucleotide - substitution of bases
• but the genetic code is degenerate meaning no change to the structure

Question 3

what is a mis-sense mutation

Answer 3

• one nucleotide is REPLACED with another nucleotide - substitution of bases
• changes the base sequence, changes the structure

Question 4

what is a non-sense mutation

Answer 4

• one nucleotide is REPLACED with another nucleotide - substitution of bases
• changes the sequence to a STOP
• stops the translation of the chain prematurely
• unlikely that the protein can carry out the function correctly

Question 5

what is a frame shift

Answer 5

• a nucleotide is lost from the normal sequence - deletion of a base
• the sequence is now completely different
• complementary to different anticodons