Question

Hannah is trying to figure out how tooth size is determined in two different wolves. In wolf 1, the copies of the gene are different from each other. In wolf 2, the copies of the gene are the same as each other. How does this affect how many types of proteins there are in each tooth cell?
Responses

a
Wolf 1 has one type of protein for the tooth size feature. Wolf 2 has one type of protein for the tooth size feature.
Wolf 1 has one type of protein for the tooth size feature. Wolf 2 has one type of protein for the tooth size feature.

b
Wolf 1 has two types of protein for the tooth size feature. Wolf 2 has one type of protein for the tooth size feature.
Wolf 1 has two types of protein for the tooth size feature. Wolf 2 has one type of protein for the tooth size feature.

c
Wolf 1 has two types of protein for the tooth size feature. Wolf 2 has two types of protein for the tooth size feature.
Wolf 1 has two types of protein for the tooth size feature. Wolf 2 has two types of protein for the tooth size feature.

d
It is impossible to say anything about proteins from the given information.

Answer 1

Answer: b

Reason: In a diploid tooth cell each gene copy (allele) can be transcribed and translated. If the two alleles are different (heterozygous, wolf 1) they can produce two different protein variants. If the alleles are identical (homozygous, wolf 2) they produce only one protein variant. (This assumes both alleles are expressed — exceptions include imprinting or allele-specific silencing.)