An alternative form or version of a gene is a(n): A allele
B karyotype.
C homologous chromosome.
D non-homologous chromosome.

The answer is A.allele

Explanation:

An allele is a variant form of a gene. Some genes have a variety of different forms, which are located at the same position, or genetic locus, on a chromosome. Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent.

they are known to reach a speed of 21 miles per hour

supercell thunderstorms are perhaps the most violent of all thunderstorm types, and are capable of producing damaging winds, large hail, and weak-to-violent tornadoes