Which structure is used for waste excretion in earthworms?

Which structure is used for waste excretion in earthworms?

• A. Intestine
• B. Waste removal tubes
• C. Blood vessels
• D. Clitellum

Answer: (B)

Waste excretion in earthworms is handled by excretory tubules called nephridia, one or more in each body segment. These tubules filter coelomic fluid to remove metabolic wastes and then discharge them to the outside through openings along the body wall, known as nephridiopores. This system keeps the worm’s internal chemistry in balance while passing waste out efficiently. The intestine, by contrast, handles digestion and elimination of undigested material as feces, not metabolic waste. Blood vessels transport substances and wastes but do not eliminate them. The clitellum is involved in reproduction, not waste removal.

Waste excretion in earthworms is handled by excretory tubules called nephridia, one or more in each body segment. These tubules filter coelomic fluid to remove metabolic wastes and then discharge them to the outside through openings along the body wall, known as nephridiopores. This system keeps the worm’s internal chemistry in balance while passing waste out efficiently.

The intestine, by contrast, handles digestion and elimination of undigested material as feces, not metabolic waste. Blood vessels transport substances and wastes but do not eliminate them. The clitellum is involved in reproduction, not waste removal.