Read the following statements and select the incorrect ones.
(i) The co-ordinated activities of the legume and Rhizobium bacteria depend on chemical interactions between the symbiotic partners.
(ii) Leguminous roots secrete chemical attractants that attract Rhizobium bacteria living nearby.
(iii) N, P and K usually do not get deficient in soil due to their low plant requirement
(iv) Nitrogen cycle is regular circulation of nitrogen amongst living organisms with its reservoir pool in lithosphere and cycling pool in atmosphere.

Options

A. (a) (i) and (ii)
B. (b) (ii) and (iii)
C. (c) (iii) and (iv)
D. (d) (ii), (iii) and (iv)

Explanation

To solve the question, we need to analyze each of the four statements provided and determine which ones are incorrect. Let's go through them step by step.

### Step 1: Analyze Statement (i)
**Statement:** The coordinated activities of the legume and Rhizobium bacteria depend on chemical interactions between the symbiotic partners.

**Analysis:** This statement is correct. Legumes and Rhizobium bacteria engage in a symbiotic relationship where both partners interact chemically. The legumes provide shelter and carbohydrates to the bacteria, while the bacteria provide nitrogen to the legumes.

### Step 2: Analyze Statement (ii)
**Statement:** Leguminous roots secrete chemical attractants that attract Rhizobium bacteria living nearby.

**Analysis:** This statement is also correct. Leguminous plants secrete specific chemical signals (attractants) that attract Rhizobium bacteria, facilitating their symbiotic association. This process is known as chemotaxis.

### Step 3: Analyze Statement (iii)
**Statement:** N, P and K usually do not get deficient in soil due to their low plant requirement.

**Analysis:** This statement is incorrect. Nitrogen (N), phosphorus (P), and potassium (K) are essential nutrients required in significant amounts by plants. They are considered primary nutrients, and their deficiency can occur due to high demand by plants, not low requirement.

### Step 4: Analyze Statement (iv)
**Statement:** Nitrogen cycle is regular circulation of nitrogen amongst living organisms with its reservoir pool in lithosphere and cycling pool in atmosphere.

**Analysis:** This statement is also incorrect. The nitrogen cycle has its reservoir pool primarily in the atmosphere (as nitrogen gas) and a cycling pool in the lithosphere (soil). The statement incorrectly identifies the reservoir and cycling pools.

### Conclusion
Based on the analysis, the incorrect statements are:
- Statement (iii) is incorrect because N, P, and K are required in high amounts, not low.
- Statement (iv) is incorrect because the reservoir pool is in the atmosphere, not the lithosphere.

Thus, the answer to the question is that statements (iii) and (iv) are incorrect.

### Final Answer
The incorrect statements are **(iii) and (iv)**.

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