Question

question 5
sequences for the types of hemoglobin are shown.
hbb sequence in normal adult hemoglobin (hb a):
nucleotide ctg act cct gag gag aag tct
amino acid leu thr pro glu glu lys ser
hbb sequence in mutant adult hemoglobin (hb s):
nucleotide ctg act cct gtg gag aag tct
amino acid leu thr pro val glu lys ser
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 an insertion mutation.
b an inversion mutation.
c a point mutation
d a frame-shift mutation.

Explanation:

A point mutation is a change in a single nucleotide. In sickle - cell anemia, one nucleotide (GAG to GTG) is changed, which leads to a change in one amino acid (Glu to Val). Insertion mutations add nucleotides, inversion mutations reverse the order of a segment of DNA, and frame - shift mutations (caused by insertions or deletions) change the reading frame of the genetic code. Here, only one nucleotide is altered without adding, deleting, or reversing a segment of DNA.

Answer:

C. a point mutation