Juan is 12 1/5 years old. How can you tell if he is still in childhood or if he is entering adolescence?
a. by how much he weighs
b. by his grade in school
c. by his birthday
d. by physical changes

Acertain species of fish can have either long or short fins. the allele for long fins is dominant over the allele for short fins. a heterozygous, long-finned fish is crossed with a homozygous, short-finned fish. of the offspring, will have long fins and be , and will have short fins and be .