In garden peas, tall vine is dominant and short vine is recessive. if a homozygous tall plant is crossed with a homozygous short plant, what genotypes are possible in the f1 generation?

All F1 plants will be heterozygous (Tt) and will be tall.

Explanation:

As you may already know, homozygosis are beings that have the same allele. Recessive homozygotes have two recessive alleles (aa) and dominant homozygotes have two dominant alleles (AA). If two homozygous plants are crossed the result of F1 will be entirely from heterozygous plants (Aa). Heterozygotic plants assume the characteristic of the dominant alleles.

Thus, we can conclude that AA x aa will result in 100% of tall heterozygous plants (Aa).