In sac fungi, karyogamy and meiosis occur in which structure?

• A. ascus
• B. sporangium
• C. basidium
• D. conidiophore

Answer: (A)

Verified step by step guidance

1. Understand the life cycle of sac fungi (Ascomycota), which includes distinct stages such as plasmogamy, karyogamy, and meiosis.
2. Recall that karyogamy is the fusion of two haploid nuclei to form a diploid nucleus, and meiosis is the process that reduces the diploid nucleus back to haploid nuclei.
3. Identify the structure in sac fungi where these nuclear events occur; this structure is specialized for sexual reproduction.
4. Recognize that in sac fungi, the structure called the ascus is where karyogamy and meiosis take place, leading to the formation of ascospores.
5. Differentiate the ascus from other fungal structures listed (sporangium, basidium, conidiophore) by their roles and the fungal groups they belong to.