Question

The nephridia in earthworm are analogous to

• A. nematoblasts of Hydra
• B. flame cells of Planaria
• C. gills of Prawn
• D. trachea of insects.

Answer 1

The Correct Option is B

The question asks about the analogy between the nephridia of earthworms and structures in other organisms. Let's delve into the functions and structure of these components to understand the correct answer:

1. Nephridia in Earthworms: Nephridia are excretory organs found in some invertebrates, like earthworms. They function similarly to kidneys in vertebrates, helping to filter and remove waste materials from the body fluids, thus maintaining homeostasis.
2. Flame Cells of Planaria: Flame cells are the excretory organs present in flatworms, like Planaria. They play a crucial role in osmoregulation and waste removal. These cells have cilia that beat to propel waste fluids through a network of tubules to the excretory pores.
3. Other Options Explained:
   • Nematoblasts of Hydra: These are specialized cells for producing nematocysts (stinging cells), not involved in excretion.
   • Gills of Prawn: Primarily used for respiration; exchange gases like oxygen and carbon dioxide, not directly involved in excretory functions.
   • Trachea of Insects: Part of the respiratory system in insects, allowing air exchange, not related to excretion.
4. Conclusion: The analogy between the nephridia of earthworms and the flame cells of Planaria lies in their function of waste removal and osmoregulation. Both serve as excretory units, managing the balance of bodily fluids.

Therefore, the correct answer is: Flame cells of Planaria.