In nitrogen free media Chlamydomonas will form gametes
and go through sexual reproduction. During sexual reproduction two
gametes of opposite mating type (type+/type-) will fuse. As seen above
reproduction within the species C. reinhardtii involves the fusion of
cells. In order to align themselves correctly for fusion they must first
entangle their flagella after the two opposite mating types are
positioned properly the cells extend mating structures, shed their cell
walls, and fuse into a single resilient diploid zygote.