Which of the following does NOT belong to the category of Porifera?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. Hydra.
Hydra belongs to the phylum Cnidaria, not Porifera. It is a freshwater organism with a radial body symmetry and tentacles equipped with nematocysts (stinging cells) for capturing prey.
In contrast, Sycon, Spongilla, and Euplectella are Porifera (sponges), which are simple, aquatic, sessile organisms with porous bodies that filter water for food. Sponges lack true tissues and exhibit asymmetry.