In the case of dormant spores in eukaryotes, sporogenesis often occurs as a result of fertilization or karyogamy forming a diploid spore equivalent to a zygote. Therefore, zygospores are the result of sexual reproduction. Reproduction via spores involves the spreading of the spores by water or air.

How are endospore formed?

Endospore formation is usually triggered by a lack of nutrients, and usually occurs in gram-positive bacteria. In endospore formation, the bacterium divides within its cell wall, and one side then engulfs the other. Endospores enable bacteria to lie dormant for extended periods, even centuries.

What causes sporogenesis to occur in spore forming bacteria?

Sporulation. Sporulation is a drastic response undertaken by some bacteria, mostly Firmicutes, in response to extreme stress. During sporulation, the growing cell (also referred to as a vegetative cell) will forego normal cellular division to instead form an endospore.