Most of the algae of fungi are unable to survive under adverse environmental conditions. Therefore, in order to tide over these unfavourable conditions these organisms shift to the sexual mode of reproduction during which they produce male/female gametes that fuse to form the zygote. The zygote secretes a thick wall around itself and undergoes a period of rest for passing the unfavourable conditions. On the approach of favourable conditions the zygote germinates to produce the new thalli of algae and mycelium of fungi.
