Question

Sequences for the types of hemoglobin are shown.

image

Sickle-cell anemia is caused by a mutation of one nucleotide in a gene. The type of mutation that causes sickle-cell anemia is known as

A.
a point mutation.

B.
an inversion mutation.

C.
a frame-shift mutation.

D.
an insertion mutation.

Answer 1

A. a point mutation.

Specifically, sickle-cell is caused by a single base substitution (a point/missense mutation) that changes one amino acid (glutamic acid → valine) in the hemoglobin protein.