In tomato plants, Mendel found that the allele for smooth seeds (S) is dominant , while the allele for wrinkled seeds (s) is recessive . Which of these Punnett squares shows crosses between two plants heterozygous for smooth seeds? A. S s s Ss ss s Ss ss B. s s s ss ss s ss ss C. S S S SS SS s Ss Ss D. s s s ss ss s ss ss
Heterozygous means that the plant has 2 different alleles, in this case, S and s. Since we're looking for 2 heterozygous plants, both plants should be S and s, like this. | S | s ----------------- S | SS | Ss - -|--------------- s | Ss | ss So, your answer is not D or B, as D and B is homozygous for the 2 plants. It's either A or C, but none of them seem to be correct.