A phenomenon present in some fungi called Diplanetism is :

Options

A. Formation of two different types of thallus in the life cycle
B. Formation of two types of successive zoospores in the life cycle
C. Fungi existing in two morphological forms
D. Completion of life cycle in two hosts

Answer

To solve the question regarding the phenomenon called Diplanetism in some fungi, we will analyze each option provided and determine which one accurately describes Diplanetism.

### Step-by-Step Solution:

1. **Understand the term "Diplanetism":**
- Diplanetism refers to a phenomenon in certain fungi where there is a formation of two different types of successive reproductive structures or spores in the life cycle of the fungus.

2. **Evaluate Option 1:**
- **Statement:** Formation of the two different types of the thallus in the life cycle.
- **Analysis:** This option is incorrect. Diplanetism does not refer to the formation of two different types of thalli but rather to the production of different types of spores.

3. **Evaluate Option 2:**
- **Statement:** Formation of the two types of the successive juice pores in the life cycle.
- **Analysis:** This option is correct. Diplanetism involves the successive production of different types of spores (juice pores) from a single fungal organism.

4. **Evaluate Option 3:**
- **Statement:** Fungi existing in the two morphological forms.
- **Analysis:** This option is incorrect. While some fungi may exhibit different morphological forms, this does not specifically define Diplanetism.

5. **Evaluate Option 4:**
- **Statement:** Completion of the life cycle in the two hosts.
- **Analysis:** This option is incorrect. A life cycle that requires two hosts is referred to as a digenetic life cycle, not Diplanetism.

6. **Conclusion:**
- After evaluating all options, the correct answer is **Option 2: Formation of the two types of the successive juice pores in the life cycle.**