Question

In the life cycle of black bread mold, the zygospore:
A. Undergoes meiosis and produces zoospores
B. Produces spores as a part of asexual reproduction
C. Is a thick-walled dormant stage
D. Is equivalent to asci and basidia

Answer 1

Hint: The gametangia are the nuclei that are involved in sexual reproduction which are later fused and form zygosporangium which is a multinucleate structure. During the asexual reproduction sporangia that are filled with spores develops at the stalk-like hyphae at the tops.

Complete answer: Rhizopus stolonifer is a species of fungus which is commonly known as the black bread mold. Some fruits and vegetables, cheese are attacked by the substrates of the fungus. Hyphae are the extending elements of the rhizopus along with its substrates and root-like structures called rhizoids. It belongs to the group Zygomycota. Both sporangia and hyphae are haploid (n) in nature during the life cycle. During further development, new sporangia are produced by the haploid fungus in the additional cycles of reproduction.
If the fungi of opposite species mate together, these organisms can sexually reproduce by nuclear fusion. During this process, a tough and thick-walled zygosporangium is formed. The zygosporangium can withstand the unfavorable environmental conditions for months, and then they again reproduce and sustain when environmental conditions are again favorable. The zygosporangium survives in a dormant stage. The diploid cell in the rhizopus undergoes meiosis then the sporangium gets sprouted out.
Hence, the correct option is (C) is a thick-walled dormant stage.

Note: When the zygosporangia revive under favorable conditions, they produce sporangia which are placed on hyphal stalks. When the sporangia break open, their spores disseminate, and, if the spores land on appropriate and suitable substrates which favor their growth, they will germinate and continue the life cycle of the fungus.