Study the following statements and select the incorrect ones.
(i) Pyramids of energy and yearly biomass production can never be inverted, since this would violate the laws of thermodynamics.
(ii) Pyramids of standing crop and numbers can be inverted, since the number of organisms at a time does not indicate the amount of energy flowing through the system.
(iii) There are certain limitations of ecological pyramids such as they do not take into account the same species belonging to two or more trophic levels.
(iv) Saprohytes are not given any place in ecological pyramids even though they play a vital role in the ecosystem.

Options

A. I and ii
B. iii and iv
C. ii and iii
D. None of these

Answer

To determine which statements are incorrect regarding ecological pyramids, we will analyze each statement one by one.

### Step-by-Step Solution:

**Step 1: Analyze Statement (i)**
- Statement (i) claims that pyramids of energy and yearly biomass production can never be inverted, as this would violate the laws of thermodynamics.
- This statement is **correct** because the second law of thermodynamics states that energy is lost as heat when transferred between trophic levels. Therefore, pyramids of energy and biomass must always be upright.

**Step 2: Analyze Statement (ii)**
- Statement (ii) states that pyramids of standing crop and numbers can be inverted since the number of organisms at a time does not indicate the amount of energy flowing through the system.
- This statement is **correct** because pyramids of numbers can be inverted, especially in cases like parasitic food chains where fewer organisms exist at higher trophic levels.

**Step 3: Analyze Statement (iii)**
- Statement (iii) mentions that ecological pyramids have limitations, such as not accounting for the same species belonging to two or more trophic levels.
- This statement is **correct** as ecological pyramids do not consider species that may occupy multiple trophic levels, which can lead to inaccuracies in representation.

**Step 4: Analyze Statement (iv)**
- Statement (iv) states that saprophytes are not given any place in ecological pyramids, even though they play a vital role in the ecosystem.
- This statement is **correct** because saprophytes, which decompose dead organic matter, are not represented in traditional ecological pyramids, despite their importance in nutrient cycling.

### Conclusion:
After analyzing all four statements, we find that all of them are correct. Therefore, there are no incorrect statements among the options provided.

### Final Answer:
**None of the statements are incorrect.**

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