Question

Hydra recognizes it's prey by

• A. Nematocyst
• B. Special organ
• C. Chemical stimulus
• D. Mechanical stimulus

Answer 1

The correct option is A Nematocyst

In Hydra, there are nematocyst which are minute, elongated or spherical capsule. Several capsules occur on the body surface. Each is produced by a special cell called a cnidoblast and contains a coiled, hollow, usually barbed thread, which quickly turns outward from the capsule upon proper stimulation. The purpose of the thread is to ward off enemies or to capture prey. The thread contains poison which helps to capture the prey.

Thus, the correct answer is option A.