Answer: 25%
Explanation: Heterozygous means that an individual has two different versions, or alleles, of a gene. In this case, one plant has an allele for round seeds and an allele for wrinkled seeds, while the other plant also has an allele for round seeds and an allele for wrinkled seeds. When these two plants are crossed, each offspring will inherit one allele for seed shape from each parent.
The probability that an offspring will have wrinkled seeds is determined by the proportion of offspring that inherit the allele for wrinkled seeds from both parents. If both parents are heterozygous, this means that each parent has a 50% chance of passing on their allele for wrinkled seeds to their offspring. Therefore, the probability that an offspring will inherit the allele for wrinkled seeds from both parents is (0.5)(0.5) = 0.25, or 25%. This means that the probability that an offspring will have wrinkled seeds is 25%.