With reference to 'earthworms', which of the following statements is/are correct?

Question

With reference to 'earthworms', which of the following statements is/are correct?

1. Earthworms improves soil fertility and are known as farmer's friends.

2. Earthworm has two pair of hearts.

Select the correct answer from the code given below:

1. A. Only 2
2. B. Neither 1 nor 2
3. C. Both 1 and 2
4. D. Only 1 (Correct answer)

Correct Answer

Option D — Only 1

Detailed Solution & Explanation

The correct answer is Only 1.

Key Points

• Statement 1 is correct. Earthworms are rightly called the "farmer's friend". Their burrowing aerates the soil and improves drainage, and their castings enrich it with nitrogen, phosphorus and potassium. Charles Darwin devoted his last book to their role in making soil.
• Statement 2 is incorrect. An earthworm (*Pheretima posthuma*) has four pairs of hearts — not two. These are the lateral hearts and lateral oesophageal hearts, lying in segments 7 to 13.
• Only statement 1 holds, giving option (d).

Additional Information

• Earthworms breathe through their moist skin (cutaneous respiration) — they have no lungs or gills, which is why they surface when the ground is waterlogged.
• They are hermaphrodite (both sex organs in one individual) but practise cross-fertilisation, and the clitellum secretes the cocoon in which the eggs develop.
• Vermicomposting uses earthworms — commonly *Eisenia fetida* — to convert organic waste into nutrient-rich manure, and is central to organic farming.
• Earthworms belong to the phylum Annelida (segmented worms), which also includes leeches and *Nereis*.