Question

sickle - shaped red blood cells result from a mutation in the gene that codes for hemoglobin. this mutation results in sickle - cell anemia. a partial sequence of bases from a normal hemoglobin gene and a sequence that results in sickle - cell anemia are shown below. normal hemoglobin: t - g - a - g - g - t - c - t - c - c - t - csickle - cell hemoglobin: t - g - a - g - g - t - c - a - c - c - t - cwhat type of mutation is depicted in this sequence? frameshift deletion substitution insertion

Explanation:

• Frameshift mutation: Caused by insertions or deletions, shifts the reading frame. Not applicable here as only one base is changed.
• Deletion: Removes one or more nucleotides. Not the case as no base is removed.
• Substitution: Replaces one nucleotide with another. In the sequences, the seventh base 'T' in normal hemoglobin is replaced by 'A' in sickle - cell hemoglobin.
• Insertion: Adds one or more nucleotides. No new base is added.

Answer:

Substitution