Life cycle of a saprophytic fungus e.g Rhizopus

– Mycelia grow on substrate and vegetative hyphae consist of stolons and rhizoids
– Rhizoids anchor fungus on substrate and absorb nutrients
– Aerial (upright) hyphae called sporangiophores are produced
– these bear globular sporangia at their tip
– Asexual spores are produced in sporangia
– spores are not flagellated, tiny and light
– dispersed at maturity, upon released by wind, rain or animal
– under favorable conditions of warmth and moisture it germinates and give rise to new hyphae
– completing asexual life cycle
– Sexual cycle initiated by conjugation
– two hyphae of different mating types/sexes
– come in contact at their tips
– cross walls soon from behind points of contact
– the gamete cells fuse to form a zygote (diploid)
– zygote develops a thick protective wall and becomes dormant
– under favorable conditions, germinates and form a short hypha (haploid)
– hypha produces sporangium
– sporangium releases asexual spores
– grow into new mycelia
– producers of sporangia formed after meiosis.

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