Question

What is the difference between a pure tall plant and a hybrid tall plant?

Answer 1

A pea plant with one recessive gene for shortness and one dominant gene for tallness is a hybrid for that trait. A hybrid is called heterozygous, as it has two different alleles. The offspring from a pure tall pea plant, cross-pollinated with a pure short pea plant, will result in a heterozygous plant for tallness.

Answer 2

The pure tall plant has equal alleles (AA or aa) while the hybrid tall plant has one dominant and recessive allele (Aa).

Step-by-step explanation:

When we say that an organism is pure, we mean that it is homozygous. In this case we are saying that, for a given trait, its alleles are equal. This means that the allele is occurring in double dose in that organism and, consequently, the gametes generated by it will be equal. A pure tall plant has alleles equal to "AA" or "aa".

When we refer to hybrid organisms, we are referring to heterozygous organisms. In this case we are saying that, for a certain characteristic, the alleles are different. For this reason, in gametogenesis, it is possible to observe the presence of two distinct gametes. A hybrid tall plant has different "Aa" alleles.