mutations

Question 1

what is a mutation?

Answer 1

a heritable permanent change in the base sequence of DNA

Question 2

what is a point mutation?

Answer 2

a single base change

Question 3

genotypic types of point mutation

Answer 3

1. transition - purine replaced by purine

2. transversion - purine replaced by pyrimidine

Question 4

phenotypic types of point mutation

Answer 4

1. silent - no effect on aa production (non-coding, regulatory or 3rd codon)
2. missense
3. nonsense
4. fremeshift

Question 5

what is missense mutation?

Answer 5

change in base sequence, change in AA

Question 6

what is nonsense mutation?

Answer 6

Change an amino acid codon into a stop codon.

Usually result in truncated proteins and altered phenotypes

Question 7

what is fremeshift mutation

Answer 7

Result from the insertion or deletion of bases from the DNA sequence.
All codons after this position will be altered.
Usually have serious effect on protein and phenotype of organism.

Question 8

what are gross mutations?

Answer 8

substantial changes in DNA, serious consequences for protein and phenotype

Question 9

types of gross mutations

Answer 9

1. deletions
2. insertions
3. rearrangements

Question 10

what are germ line mutations?

Answer 10

occurs in the egg or sperm cell

all cells of the offspring will be affected.

Question 11

what are somatic mutations?

Answer 11

affect a limited area in body

• effect depends on when in development mutation occurs
• not transmitted to offspring
• mosaic