Mutations

Question 1

What is a mutation?

Answer 1

permanent change in sequence of bases that make up a gene?

Question 2

Mutations can occur_______

Answer 2

RANDOMLY

Question 3

What increases the rate of mutations?

Answer 3

Mutagenic agents and mutagents

Question 4

Examples of mutagenic agents?

Answer 4

• Infectious agents (bacteria and viruses (HPV) )
• chemicals e.g carcinogens like cigarettes
• Radiation, UV sunlight and Gamma x rays

Question 5

What do mutations introduce?

Answer 5

VARIATION into populations

they can have different effects in the fitness of an individual

Question 6

What is fitness?

Answer 6

ability to survive and reproduce

Question 7

What can mutations be?

Answer 7

• Neutral (no effect on fitness) genetic code degenerate
  Positive- inc fitness
  Negative- decrease fitness

Question 8

What is a silent mutation?

Answer 8

• a base change that doesn’t affect sequence of amino acids due to degenerate nature of genetic code (no change to protein)

Question 9

Substitution/point mutations?

Answer 9

• when 1 base is replaced by another and dependent on the base change a point mutation will have 1/3 outcomes

Question 10

Missense mutation?

Answer 10

• base change, changes amino acid specified by codon
• new codon codes for different amino acid
• changes protein structure may result in protein that is still functional or nonfunctional

Question 11

Nonsense mutation?

Answer 11

base change results in a stop codon where an amino acid should be
causes translation to stop prematurely
non functional protein

Question 12

Deletion & addition mutations?

Answer 12

bases deleted added causes FRAME SHIFT
(reading frames of triplets change)
- genetic code is read in codons therefore changes reading frame of sequence, frame shift mutation

Question 13

What can a change in sequence of bases cause?

Answer 13

• diff amino acid, non functional protein
• diff 1y structure
• diff bodnign
• diff 3y strcuture
• no e/s complexes