Question

Gregor Mendel crossed homozygous tall plants (TT) with homozygous short plants (tt). All the resulting offspring were tall. From these results, what conclusion did Mendel draw? Tallness is a dominant trait. The word homozygous always means dominant. Only dominant alleles are passed on to offspring. The alleles of the offspring were recessive.

Answer 1

Answer: Tallness is a dominant trait.

Explanation:

• When Mendel crossed tall plants TT with short plants tt , the cross that resulted is shown in the punnet square  attached with the answer.

• From the punnet square it is seen that the genotype of all the progenies comes out to be Tt. Such a condition is known as heterozygous condition.

• Since in the genotype Tt, 2 different alleles are present but the phenotype corresponds to the one encoded by the allele T we can say that allele T is dominant over t.

• Further, we can reject other options as we can see that

1.Both recessive and dominant alleles are passed on to the offspring.

2. Homozygous condition is not equivalent to dominant.

3. The alleles of the offspring were not recessive but they were in heterozygous condition.

So, the only conclusion that can be made from Mendel's cross is that tallness is a dominant trait as allele T is dominant over t.

Answer 2

The answer is A , tallness is the dominate trait.