Sickle cell anaemia

Question 1

4 polypeptides in haemoglobin

Answer 1

2 α chains produced by 2 HBA genes, 2 β chains produced by HBB gene

Question 2

Nature of mutation

Answer 2

One base substitution in HBB gene

Question 3

Before and after sequence

Answer 3

CTC-GAG turns into CAC-GTG

Question 4

Restriction site for normal vs affected allele

Answer 4

Normal allele has restriction site for Mstll enzyme but mutant allele does not, Mstll creates two fragments of normal DNA (0.2kb & 1.2k) but only one fragment from mutant DNA (1.4kb)

Question 5

Haemoglobin in normal vs mutant red blood cell

Answer 5

In normal RBC haemoglobin floats freely, in mutant RBC haemoglobin is clumped into rods

Question 6

Sickle RBC affects on function

Answer 6

Sickle RBC cannot move as easily through vessels which can create clots, and sickle RBCs die quicker than normal and can create lack of oxygen to parts of body

Question 7

Sickle cell anemia

Answer 7

Recessive genetic condition in which mutated form of haemoglobin distorts RBC

Question 8

Symptoms of sickle cell anemia

Answer 8

Dizziness, fatigue, low oxygen in body, abnormal breakdown of red blood cells, shortness of breath

Question 9

Impact of mutation on protein

Answer 9

Changes glutamic acid to valine, creates different protein shape