The main purpose of bacterial spores—known as endospores—is to protect bacterial cells so they can survive extreme, harsh conditions. In comparison, fungi reproduce both sexually and asexually through the formation of spores. Asexual spores are formed by the hyphae of one organism; the organisms that form from these spores are identical to their parents. Sexual spores result from the fusion of nuclei from two strains of the same species of fungus; organisms from sexual spores derive characteristics from each parent.