In which one of the following organisms its excretory organs are correctly stated? (a) Humans – Kidneys, sebaceous glands and tear glands (b) Earthworm – Pharyngeal, integumentary and septal nephridia (c) Cockroach – Malpighian tubules and enteric caeca (d) Frog – Kidneys, skin and buccal epithelium
Option B Nephridia is the excretory organ of the earthworm. Earthworms have three types of nephridial structures called as septal, integumentary and pharyngeal nephridia. These three nephridial structures are present on different positions in the body and also vary in structures. Septal and pharyngeal nephridia are both enteronephric i.e., nitrogen products are expelled in gut. Integumentary nephridia is exonephric i.e., nitrogen waste products are directly discharged outside.
