204
BIOLOGY XI: Chapter 7, PROTISTS AND FUNGI
Fig: 7.15 Reproduction in Rhizopus
the mycelium by the formation of septa. Plus and minus nuclei then fuse to form a diploid nucleus, the zygote. The zygote develops into a zygospore. The wall of the zygospore is thick and resistant to unfavourable conditions. The division or phylum name refers to the zygospore. Zygospores germinate under favourable conditions and divide by meiosis. The wall of the zygospore splits and hyphae grows upward. The tip of the hypha develops into a sporangium. The sporangium contains many nuclei. The wall of the sporangium ruptures and the spores are liberated. Each spore grows into a new plus or minus strain of mycelium. Thus the life cycle of Rhizopus is continued. Q. What is the purpose of sporangiophores?