Some fungi have elaborate mechanisms for dispersing spores. For example, the 'squirt gun' fungus Pilobolus, which grows in cow dung, forcibly shoots off tiny black sporangia filled with spores. Any sporangia that are flung onto fresh grass are likely to be eaten by a grazing cow, passed through its digestive system unharmed, and deposited in a new batch of dung. The spores carried within the sporangia are perfectly positioned to grow into a new mycelium. Pilobolus is a zygomycete, and the sporangia just described produce asexual spores. In contrast, which of the following best describes what happens during the sexual phase of its life cycle? a. It produces eight ascospores in each ascus. b. It produces basidiospores that grow into mushrooms. c. It produces motile sperm and eggs. d. Hyphae from two compatible mating types fuse and form a zygosporangium.

Verified step by step guidance

1. Identify the type of fungus and its reproduction method: Pilobolus is a zygomycete fungus that reproduces asexually by producing sporangia filled with spores.
2. Understand the sexual reproduction in zygomycetes: In zygomycetes, sexual reproduction typically involves the fusion of hyphae from two different mating types.
3. Analyze the options given: Option a refers to ascospores produced in asci, which is characteristic of ascomycetes. Option b mentions basidiospores and mushrooms, which are features of basidiomycetes. Option c describes the production of motile sperm and eggs, which is not typical in fungal reproduction.
4. Match the correct process with zygomycetes: Option d describes the fusion of hyphae from two compatible mating types to form a zygosporangium, which is a key feature of zygomycete sexual reproduction.
5. Conclude the correct answer: The correct answer is d, as it accurately describes the sexual phase of the life cycle in zygomycetes like Pilobolus.

Key Concepts

Fungal Reproduction

Fungi can reproduce both asexually and sexually. Asexual reproduction often involves the production of spores, which can disperse and germinate into new individuals. In contrast, sexual reproduction in fungi typically involves the fusion of specialized reproductive structures from two compatible mating types, leading to the formation of zygospores or other types of spores, depending on the fungal group.

Zygomycetes

Zygomycetes are a group of fungi characterized by their ability to form zygosporangia during sexual reproduction. These structures arise from the fusion of hyphae from two different mating types, resulting in a thick-walled zygospore that can withstand harsh conditions. This group includes fungi like Pilobolus, which are known for their unique spore dispersal mechanisms.

Sporangia and Spores

Sporangia are specialized structures in fungi that produce and contain spores. In the case of Pilobolus, the sporangia are forcibly ejected to disperse spores effectively. Spores are the reproductive units that can develop into new fungal organisms, either through asexual means or as part of the sexual reproductive cycle, depending on the environmental conditions and the life stage of the fungus.