Question

Hypnotoxin is produced by
A. Sponges
B. Bath sponge
C. Nematocysts
D. Leucosolenia

Answer 1

Hint:- Cnidocytes/Cnidoblasts on the tentacles of Cnidarians have stinging capsules. These can render the prey unconscious as it is a neurotoxin/hypnotoxin.

Complete answer:
Minute, elongated or spherical capsules formed exclusively by members of the Cnidaria phylum. Many such capsules exist on the surface of the body. Each is formed by a special cell called a cnidoblast and contains a coiled, hollow, usually barbed thread that, upon proper stimulation, quickly turns outward from the capsule. The purpose of the thread, which often contains poison, is to ward off or catch prey from enemies.
Nematocysts, which are modified epidermal interstitial cells, are cell organelles found in specialized cells called cnidocytes or cnidoblasts. A Cnidoblast is an oval or rounded cell lying on the basal side with a prominent nucleus. An oval or pyriform sac or bladder that is filled with a toxin called hypnotoxin, a combination of proteins and phenols, is found within the cnidoblast.
A lid-like structure on the top of the capsule pops aside when triggered by chemical or mechanical signals, and the thread drifts explosively with a twisting movement. The barbs work like a drill as eversion and twisting continue, penetrating into (and pulling the thread into) the foreign target. It passes through the hollow thread, penetrating and paralyzing the tissues of the victim if a toxin is present. The thread then separates from the nematocyst after eversion.
Hence, the correct answer is (c) Nematocysts.

Note:- Nematocysts are a type of cnidae and jellyfish and other cnidarians are isolated from other animals by the presence of cnidae. Cnidae are among the most complex recognized products of intracellular secretion.