What is it called when part of a cell membrane closes around a molecule to allow the molecule to enter the cell?

This is called endocytosis

Sexual reproduction in the fungi consists of three sequential stages: plasmogamy, karyogamy, and meiosis. The diploid chromosomes are pulled apart into two daughter cells, each containing a single set of chromosomes (a haploid state). ... In most fungi the zygote is the only cell in the entire life cycle that is diploid.