Question

1. what type of mutation causes sickle - cell anemia?

silent mutation
chromosomal mutation
missense mutation
nonsense mutation

Explanation:

Sickle - cell anemia is caused by a single - base substitution in the gene for the beta - chain of hemoglobin. This substitution changes one amino acid in the polypeptide chain, which is a characteristic of a missense mutation. A silent mutation does not change the amino - acid sequence, a chromosomal mutation involves changes in chromosome structure or number, and a nonsense mutation creates a premature stop codon.

Answer:

C. missense mutation