Which of the following statements is correct about excretion in earthworm ?
(i) Earthworm is mainly ureotelic
(ii) Septal nephridia, present on both sides of intersegmental septa of segment 15 to the last open into intestine
(iii) Integumentary nephridia, attached to lining of body wall of segment 3 to the last, open on the body surface
(iv) Different types of nephridia are basicaly similar in structure
(v) Nephridia regulate the volume and composition of body fluids.

Options

A. (i) and (iv)
B. (iv) and (v)
C. (i),(ii),(iii)
D. All of these

Answer

To determine which statements about excretion in earthworms are correct, let's analyze each statement step by step.

### Step 1: Understand the Excretory System of Earthworms
Earthworms possess specialized excretory organs called nephridia. There are three types of nephridia: segmental, integumentary, and pharyngeal.

### Step 2: Evaluate Each Statement
1. **Statement (i): Earthworm is mainly ureotelic.**
- Earthworms excrete waste primarily in the form of ammonia, which classifies them as ureotelic. This statement is **correct**.

2. **Statement (ii): Septal nephridia, present on both sides of intersegmental septa of segment 15 to the last, open into the intestine.**
- Segmental nephridia are indeed present on both sides of the intersegmental septa from segment 15 to the last segment and they open into the intestine. This statement is **correct**.

3. **Statement (iii): Integumentary nephridia, attached to lining of body wall of segment 3 to the last, open on the body surface.**
- Integumentary nephridia are found below the skin and open to the body surface, starting from segment 3 to the last segment. This statement is **correct**.

4. **Statement (iv): Different types of nephridia are basically similar in structure.**
- Although there are different types of nephridia, they share a basic structural similarity. This statement is **correct**.

5. **Statement (v): Nephridia regulate the volume and composition of body fluids.**
- The primary function of nephridia is indeed to regulate the volume and composition of body fluids. This statement is **correct**.

### Conclusion
All the statements (i, ii, iii, iv, and v) about excretion in earthworms are correct.

### Final Answer
The correct answer is that all of the statements are true.

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