Question

Sequences for the types of hemoglobin are shown.



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 insertion mutation.
c
an inversion mutation.
d
a frame-shift mutation.

Answer 1

Sickle-cell anemia is caused by a mutation in the hemoglobin gene where a single nucleotide is changed, resulting in the substitution of one amino acid for another in the hemoglobin protein. This type of mutation is known as a **point mutation**.

Therefore, the correct answer is:

**a. a point mutation.**