Mutation and Gene expression

Question 1

What are mutations (3 significant answers)

Answer 1

1. Change in the nucleotide sequence of DNA
2. May occur in somatic cells (not passed to offspring)
3. May occur in gametes and be passed to off springs

Question 2

What is point mutation and what are the 3 types

Answer 2

Point mutation: single base change, base-pair substitution

1. Silent mutation
   2.Missense
   3.Nonsense

Question 3

What is a silent mutation and does it cause any changes

Answer 3

No amino acid change
Redundancy in code
AA stays the same

Question 4

What is a missense mutation and does it cause any changes

Answer 4

A change in one amino acid
May change or not depending on how important the amino acid is

Question 5

What is nonsense mutation and does it cause any changes

Answer 5

Changes amino acid to stop codon
Its a premature stop codon so it causes AA not to be made at all

Question 6

What is a frame shift mutation and the two types

Answer 6

Frameshift: Shift in the reading frame (changes everything downstream)

1.Insertions
2.Deletion

Question 7

What is insertion mutation

Answer 7

Adding base(s)

Question 8

What is deletion mutation

Answer 8

losing base(s)

Question 9

Is an frameshift mutation cause worse effects near beginning or ending of mRNA sequence

Answer 9

Near the beginning of the mRNA sequence as more AA can be changed

Question 10

What is the difference between point and frameshift mutation

Answer 10

Point: only one aa affected
Frameshift: everything downstream of it is affected by the mutation

Question 11

What (2) causes mutations

Answer 11

1. Spontaneous mutations: occurs as an result of natural processes in cells ex: incorrect base pairing by DNA polymerase during replication
2. Induced mutations: caused by agents (mutagens) outside of the cell