Mendel crossed purebred purple-flowered plants with purebred white-flowered plants, and all of the resulting offspring produced purple flowers. The offspring are all , and the allele for purple flowers is .

Heterozygous and dominant

Explanation:

When Mendel performed the purebred purple flower with the purebred white flower he found that the purple flowers were obtained.

Suppose,

the genotype of the purple flower is- PP (purebred)

the genotype of white flower- pp ( purebred)

crossing them we obtain

                         PP      x     pp

                            P          P

                 p       Pp        Pp

                p       Pp        Pp

We see that all the offspring obtained are heterozygous (Pp) and are purple colored.

This shows that the allele for the purple flower is dominant.

Thus, heterozygous and dominant is correct.

it creates acid rain