DNA Mutations

Question 1

Where do mutations occur when they are
- Somatic
- Germ-line
- Autosomal
- X-linked and Y-linked

Answer 1

Somatic - any cell except germ cells
Germ-line - Gametes
Autosomal - Autosomes
X + Y - linked - Genes on the X and Y chromosomes

Question 2

What are the 3 point mutations and what are the outcomes

Answer 2

Silent - new codon still codes for the same AA
Missense - new codon codes for different AA
Nonsense - new codon codes for a stop codon

Question 3

Point mutations can be transitions or transversions - explain

Answer 3

Transition - Pyrimidine replaces a pyrimidine and purine replaces purine
Transversion - Pyrimidine and purine are interchanged

Question 4

What is the reason for a frameshift mutation

Answer 4

Insertion or deletion of base

Question 5

Give 3 examples of diseases caused by mutations and the type of mutation that ocurred

Answer 5

Sickle-cell anemia - base substitution
Muscular dystrophy - insertion or deletion
Cystic fibrosis