Answer:
1/2 or 50%
Step-by-step explanation:
Let's assume that the allele "T" gives a "tall" phenotype while the allele "t" gives a "short" phenotype to the plants. The genotype of the homozygous short plants would be "tt". The genotype of the F1 heterozygous tall plant would be "Tt". A cross between "Tt" and "tt" would give progeny in following ratio=
Tt x tt = 1/2 tall (Tt): 1/2 short (tt)
Therefore, there is 1/2 or 50% chance that the seeds from the given cross produce a tall plant.