When Mendel crossed purebred short plants with purebred tall plants

Question

All off spring weretall
All off spring were short

Answer 1

When Gregor Mendel crossed purebred short plants with purebred tall plants, all of the offspring were tall. Mendel's experiments on pea plants showed that the tall phenotype is dominant over the short phenotype. Therefore, when he crossed purebred tall (homozygous dominant) plants (T) with purebred short (homozygous recessive) plants (t), the offspring (F1 generation) all exhibited the tall phenotype (Tt).

So, the correct answer to your question is: All offspring were tall.