Primary succession is development of biotic communities on :-
(a) Newly exposed habitat
(b) Cleared forest area
(c) Freshly harvested crop field
(d) Pond filled after a dry season

Options

A. only a
B. a & d
C. a, c, d
D. b, c, d

Answer

To solve the question regarding primary succession and its development of biotic communities, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Succession**:
- Ecological succession refers to the process of change in the species structure of an ecological community over time. It can be classified into two main types: primary succession and secondary succession.

2. **Define Primary Succession**:
- Primary succession occurs in an area where there is no pre-existing soil or biological community. This typically happens on newly exposed habitats, such as after a volcanic eruption or glacial retreat, where life has not previously existed.

3. **Analyze the Options**:
- (a) **Newly exposed habitat**: This option refers to areas that have been recently formed or exposed, such as bare rock or land after a glacier melts. This is a classic example of primary succession.
- (b) **Cleared forest area**: This area has been disturbed but still has soil and some remnants of the previous biological community, making it more suitable for secondary succession.
- (c) **Freshly harvested crop field**: Similar to a cleared forest, this area has been disturbed but retains soil and some biological components, indicating secondary succession.
- (d) **Pond filled after a dry season**: This scenario involves a temporary change in water levels, which does not represent primary succession as the area is not newly exposed.

4. **Identify the Correct Answer**:
- Based on the definitions and analysis, the correct answer is (a) **Newly exposed habitat**. This is where primary succession occurs as it involves the development of biotic communities in an area that has never been previously colonized by life.

### Final Answer:
(a) Newly exposed habitat