The gametophytes in seed plants, like pine trees and oak trees, are unisexual and microscopic. They are found inside part of the sporophyte and rely completely on the sporophyte for nutrients. For example, in a pine tree, the male gametophyte that produces sperm is found inside a pollen grain.lternation of generations is a type of life cycle found in all plants and some algae species. This process involves a multicellular diploid generation called a sporophyte and a multicellular haploid generation called a gametophyte.