Compare and contrast the reaction between 1) halogens and alkanes and between 2) halogens and alkenes.

The answer is D. Species A will have fewer phenotypes.
Alleles are alternative forms of a gene. In species A, the leaf color is controlled by two alleles, for example, P and Q. They will have three possible genotypes - PP, PQ, and QQ. Three different genotypes give maximum three phenotypes.In species B, leaf color is controlled by three alleles, for example, L, M, and N. They will have six different genotypes - LL, LM, LN, MM, MN, and NN. Six different genotypes give maximum 6 phenotypes.