gene/point mutations

Question 1

what are the 3 types of mutations?

Answer 1

• gene/point

- chromosome/ block

Question 2

define gene/point mutations

Answer 2

• localized changes in the base sequence of a DNA strand caused by a mutagen or an error during replication

Question 3

what are the three types of mutations within gene mutations?

Answer 3

1) substitution
2) insertion
3) deletion

Question 4

what is substitution in gene mutations?

Answer 4

one nucleotide is replaced by a different nucleotide resulting in:
- synonymous 
- missense
- nonsense 
= sickle cell disease

Question 5

what is the insertion in gene mutations?

Answer 5

addition of one or more nucleotides base pairs into a DNA sequence
results in:
- frameshift

Question 6

what is a deletion in gene mutations?

Answer 6

a nucleotide is removed from the DNA strand
= cystic fibrosis
results in:
- frameshift

Question 7

define synonymous

Answer 7

more than one triplet can code for same amino acid = same amino acid + no effect on the protein produced

Question 8

define missense

Answer 8

one base change = one amino acid difference in the protein produced

Question 9

define nonsense

Answer 9

one base change = stop codon occurring prematurely = halts translation= incomplete protein that is likely to have no biological use

Question 10

define frameshift

Answer 10

every following codon is affected as the frame of reference has moved = leading to translation halting and protein failing