Which term describes the stationary cnidarian body form with tentacles for feeding?

Which term describes the stationary cnidarian body form with tentacles for feeding?

• A. Nematocyst
• B. Spicules
• C. Plankton
• D. Polyp

Answer: (D)

Cnidarians come in two basic body plans: a sessile polyp and a free-swimming medusa. The stationary form with tentacles used to capture prey is the polyp. It stays attached to a surface, with its mouth and tentacles facing upward to seize food, often reproducing asexually to form colonies like corals or hydras. The tentacles are equipped with cnidocytes that sting prey and move it toward the mouth. In contrast, the medusa is the drifting, bell-shaped form, seen in jellyfish, which swims to encounter prey. The other terms refer to structures or non‑form concepts: nematocysts are the stinging cells, spicules are skeletal elements in sponges, and plankton are drifting organisms.