Answer:

To predict the resulting genotypes and phenotypes of a monohybrid cross between a tall purebred pea plant (TT) and a short purebred pea plant (tt), we can use a Punnett square.

Let's represent the tall allele as "T" and the short allele as "t".

The genotype of the tall purebred pea plant is TT (both alleles are tall) and the genotype of the short purebred pea plant is tt (both alleles are short).

The Punnett square for this cross would look like this:

| T | T |

-----------------

t | Tt | Tt |

From the Punnett square, we can see that all the offspring (F1 generation) will have the genotype Tt, which means they will be heterozygous for the height trait.

In terms of phenotypes, the "T" allele is dominant, and the "t" allele is recessive. This means that the tall phenotype will be expressed in the presence of at least one dominant allele (T), while the short phenotype will only be expressed in the absence of the dominant allele (tt).

Therefore, all the offspring from this cross will be tall (Tall phenotype) because they have at least one dominant "T" allele.

To summarize:

- Genotypes of offspring (F1 generation): All Tt (heterozygous for height)

- Phenotypes of offspring (F1 generation): All tall