In some fungi such as……………, the fusion of two haploid cells immediately results in diploid cell while in other group of fungi like …………., an intervening dikaryotic stage occurs, called dikaryophase.

Options

A. Phycomycetes , Basidomycetes
B. Basidomycetes, Ascomycetes
C. Ascomycetes, Phycomycetes
D. Phycomycetes , Deuteromycetes

Answer

To solve the question, we need to identify two groups of fungi based on their reproductive processes.

### Step-by-Step Solution:

1. **Understanding Fungal Reproduction**:
- Fungi can reproduce sexually and asexually. The sexual reproduction involves two main processes: plasmogamy (fusion of cytoplasm) and karyogamy (fusion of nuclei).

2. **Identifying the First Group of Fungi**:
- The question states that in some fungi, the fusion of two haploid cells immediately results in a diploid cell. This characteristic is typical of the group known as **Phycomycetes**. In this group, the zygote formed after karyogamy directly becomes a diploid organism.

3. **Identifying the Second Group of Fungi**:
- The question also mentions another group of fungi where an intervening dikaryotic stage occurs, known as the dikaryophase. This is characteristic of **Ascomycetes** and **Basidiomycetes**. In these groups, after plasmogamy, the two haploid nuclei coexist in the same cell without immediately fusing, leading to a dikaryotic stage before karyogamy occurs.

4. **Finalizing the Answer**:
- Therefore, the correct answer to the question is:
- In some fungi such as **Phycomycetes**, the fusion of two haploid cells immediately results in a diploid cell, while in another group of fungi like **Ascomycetes** or **Basidiomycetes**, an intervening dikaryotic stage occurs, called dikaryophase.

### Final Answer:
In some fungi such as **Phycomycetes**, the fusion of two haploid cells immediately results in a diploid cell, while in other groups of fungi like **Ascomycetes** or **Basidiomycetes**, an intervening dikaryotic stage occurs, called dikaryophase.