3.5: DNA mutations

Question 1

Hotspots

Answer 1

Site in genome that are prone to mutation.

Question 2

Germ cells vs Somatic cells (compare mutation rates)

Answer 2

Germ cells: Reproductive cells (egg and sperm)
Somatic cells: All the other cells
Rate of mutation is grater in somatic because DNA repair mechanisms are more efficient in germ cells

Question 3

Point mutation

Answer 3

Mutation in which one base pair is replaced by a different base pair.

Question 4

Synonymous (silent) mutations

Answer 4

Point mutation in which the mutated base pair codes for the same amino acid as the original base pair.
Neutral or harmless mutation.

Question 5

Nonsynonymous (missense) mutations

Answer 5

Point mutation in which the mutated base pair codes for a different amino acid than the original base pair.
Can either be harmful or harmless, even beneficial.

Question 6

Nonsense mutation

Answer 6

Point mutation in which the mutated base pair codes for a stop codon and terminates translation.
Almost always harmful

Question 7

Insertion/Deletion mutations

Answer 7

Mutations involving the deletion or insertion of a small number of nucleotides.

Question 8

Frameshift mutation

Answer 8

Insertion/deletion mutations that are not exact multiples of 3, and thus completely alters the amino acid sequences.
Mutated protein becomes nonfunctional.