Question

Mendel crossed tall pea plants with short pea plants. The offspring were all tall plants.

Which allele is recessive?

Which allele is dominant?

Answer 1

Recessive allele: short (t)

Dominant allele: tall (T)

Reason: If a true-breeding tall (TT) is crossed with a true-breeding short (tt), all offspring are Tt and show the tall phenotype, so tall is dominant over short.