When fungi reproduce sexually, what occurs?

• A. Mitosis only
• B. Plasmogamy, Karyogamy, and Meiosis
• C. Binary fission
• D. Spore germination

Answer: (B)

Fungal sexual reproduction centers on bringing together genetic material through a sequence of cytoplasmic and nuclear fusion before producing haploid offspring. First, plasmogamy occurs, where the cytoplasm of two compatible fungal cells merges, creating a cell that contains two distinct nuclei (a dikaryotic stage). Then, karyogamy happens, the fusion of those two nuclei to form a diploid nucleus. This diploid nucleus then undergoes meiosis, generating haploid spores that can disperse and grow into new fungi. This combination of cytoplasmic fusion, nuclear fusion, and meiotic division is what drives genetic recombination in sexual fungal reproduction.

Mitosis is a general cell division process used for growth and some asexual reproduction, not the specific sequence that produces sexually derived spores. Binary fission is how many bacteria divide, not how fungi reproduce. Spore germination is the growth of a spore into a new organism after its formation, but it is a later step, not the sexual reproductive sequence that creates the spores through meiosis.