Which of the following is false?
I. Quantity of biomass in a trophic level at a particular period is called standing crop.
II. The energy content in a trophic level is determined by considering a few individuals of a species in that trophical level.
III. The succession that occurs in nearly cooled lava is called primary succession.
IV. Rate of succession is faster in the secondary succession V. Phytoplanktons are the pioneers in aquatic succession

Options

A. Only II
B. Only III
C. O n lyV
D. Only I and IV

Answer

To determine which statement is false among the given options, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement I**: "Quantity of biomass in a trophic level at a particular period is called standing crop."
- This statement is **true**. The standing crop refers to the total biomass present in a particular trophic level at a specific time.

2. **Statement II**: "The energy content in a trophic level is determined by considering a few individuals of a species in that trophic level."
- This statement is **false**. The energy content in a trophic level should be assessed by considering the entire population of organisms in that trophic level, not just a few individuals. A few individuals may not represent the energy dynamics accurately.

3. **Statement III**: "The succession that occurs in nearly cooled lava is called primary succession."
- This statement is **true**. Primary succession occurs in lifeless areas where soil has not yet formed, such as on newly formed volcanic lava.

4. **Statement IV**: "Rate of succession is faster in the secondary succession."
- This statement is **true**. Secondary succession occurs in areas where a disturbance has destroyed an existing community but left the soil intact, allowing for a quicker recovery compared to primary succession.

5. **Statement V**: "Phytoplanktons are the pioneers in aquatic succession."
- This statement is **true**. Phytoplankton are often the first organisms to colonize aquatic environments, making them pioneers in aquatic succession.

### Conclusion:
The false statement among the options provided is **Statement II**.