How can you tell the gender of a corn plant?
You are correct that some plant species have individuals of two types: those producing only flowers that make pollen and those producing only flowers that produce egg cells that develop into seeds. In these species, the plants that produce only pollen are often referred to as "male" and the seed-producing plants are referred to as "female". American holly is an example of a species that follows this pattern.
Corn plants produce pollen and eggs in separate flowers, but those flowers are on the same plant. The tassel is the "male" flower, which produces the pollen, and the ear is the "female" flower. The silks, which grow out of the ear, are the pistils, which catch the pollen grains. Each silk is attached to a single egg cell, which, if fertilized, will develop into a corn kernel.
So, to answer your question, all corn plants are both "genders".