Consider the following statements and select the correct option stating which ones are true (T) and which ones are false (F).
(i) Pyramid of biomass is upright in the forest ecosystem and inverted in the grassland ecosystem.
(ii) Pyramid of numbers is inverted in grassland and upright in aquatic ecosystem.
(iii)Pyramid of energy depicts the rate of energy flow or productivity at successive trophic levels .
(iv) Ecological pyramids have no place for detritivores and decomposers though they play an important role in an ecosystem.

Options

A. `{:(i,ii,iii,iv),(F,F,T,T):}`
B. `{:(i,ii,iii,iv),(T,F,T,T):}`
C. `{:(i,ii,iii,iv),(F,T,F,F):}`
D. `{:(i,ii,iii,iv),(T,F,F,T):}`

Answer

To solve the question, we need to evaluate each of the four statements regarding ecological pyramids and determine if they are true (T) or false (F).

### Step-by-Step Solution:

1. **Evaluate Statement (i)**: "Pyramid of biomass is upright in the forest ecosystem and inverted in the grassland ecosystem."
- The pyramid of biomass is typically upright in grassland ecosystems, where the biomass of producers (plants) is greater than that of primary consumers (herbivores). In forest ecosystems, the pyramid of biomass can be inverted due to the high biomass of primary consumers compared to the relatively low biomass of producers (trees).
- **Conclusion**: This statement is **False (F)**.

2. **Evaluate Statement (ii)**: "Pyramid of numbers is inverted in grassland and upright in aquatic ecosystem."
- The pyramid of numbers is generally upright in grassland ecosystems, as there are more producers than consumers. In aquatic ecosystems, it can be inverted because a few large producers (like phytoplankton) can support many small consumers (like zooplankton).
- **Conclusion**: This statement is **False (F)**.

3. **Evaluate Statement (iii)**: "Pyramid of energy depicts the rate of energy flow or productivity at successive trophic levels."
- The pyramid of energy accurately represents the flow of energy through an ecosystem, showing that energy decreases at each trophic level due to energy loss (e.g., through metabolic processes). It is always upright.
- **Conclusion**: This statement is **True (T)**.

4. **Evaluate Statement (iv)**: "Ecological pyramids have no place for detritivores and decomposers though they play an important role in an ecosystem."
- Ecological pyramids typically do not include detritivores and decomposers, even though they are crucial for nutrient cycling in ecosystems. They are often omitted from the traditional pyramids.
- **Conclusion**: This statement is **True (T)**.

### Final Summary of Statements:
- (i) F
- (ii) F
- (iii) T
- (iv) T

### Correct Option:
The correct option indicating the true (T) and false (F) statements is:
- (i) F, (ii) F, (iii) T, (iv) T