Chlamydomonas zygote. Coloured scanning electron micrograph of a zygote of the single-celled green alga Chlamydomonas sp. A zygote is formed when gametes (male and female sex cells) fuse during sexual reproduction. Since each cell has two flagellae for propulsion, the zygote at first has four flagellae but these are lost as a spiny wall develops. This wall (seen here) protects the zygote from harsh conditions. Meiosis cell division occurs, and at germination four haploid vegetative cells are released. Chlamydomonas are commonly found in pond water. Magnification: x2,149 at 6x7cm size. Magnification: x6000 at 8x10 inch size.