Final answer:
In a genetic cross between a homozygous tall plant with homozygous purple flowers and a homozygous short plant with heterozygous purple flowers, the F2 generation is expected to have approximately 7 short plants out of 28 individuals sampled.
Step-by-step explanation:
In a genetic cross between a homozygous tall plant with homozygous purple flowers and a homozygous short plant with heterozygous purple flowers, the probability of obtaining short plants in the F2 generation can be determined using a Punnett square. Let's represent tall plants with T and short plants with t, and purple flowers with P and white flowers with p.
The homozygous tall plant has the genotype TT with purple flowers (PP), while the homozygous short plant has the genotype tt with both purple (Pp) and white (pp) flower options. When crossed, the F1 generation will all have the genotype Tt with purple flowers (Pp). To find the expected ratio of short plants in the F2 generation, we need to perform another cross using the genotype Tt with purple flowers (Pp).
The Punnett square for this cross would be as follows:
T t T TT TTt Tt Tt
From this Punnett square, we can see that there is a 25% chance of obtaining a short plant with the genotype tt. If we sample 28 individuals from the F2 generation, we can expect approximately 7 short plants.