Plasmogamy is immediately followed by karyogamy in

Options

A. Ascomycetes
B. Basidiomycetes
C. Deuteromycetes
D. Phycomycetes

Answer

**Step-by-Step Solution:**

1. **Understanding Plasmogamy and Karyogamy:**
- Plasmogamy refers to the fusion of the protoplasts (cell bodies) of two fungal cells, resulting in a cell that contains two nuclei (this stage is called a dikaryon).
- Karyogamy is the subsequent fusion of these two nuclei to form a diploid nucleus.

2. **Identifying the Life Cycle Stages:**
- In the life cycle of fungi, after plasmogamy, there is typically a dikaryotic stage where the cell has two nuclei (n + n).
- Karyogamy usually occurs after a period of time, leading to the formation of a diploid cell (2n).

3. **Analyzing the Fungal Groups:**
- The question asks which group of fungi has plasmogamy immediately followed by karyogamy without a dikaryotic stage.
- Ascomycetes and Basidiomycetes typically have a dikaryotic stage, where plasmogamy occurs before karyogamy.
- Deuteromycetes (imperfect fungi) also have a similar life cycle.

4. **Identifying the Exception:**
- Phycomycetes (also known as Zygomycetes) do not have a dikaryotic stage. In these fungi, plasmogamy is directly followed by karyogamy without any significant delay.

5. **Conclusion:**
- Therefore, the correct answer is **Phycomycetes**, where plasmogamy is immediately followed by karyogamy.

**Final Answer:**
Plasmogamy is immediately followed by karyogamy in **Phycomycetes**.

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