How a nematocyst is triggered?

How a nematocyst is triggered?

The cell’s thread is coiled under pressure and wrapped around a stinging barb. When potential prey makes contact with the tentacles of a polyp, the nematocyst cell is stimulated. This causes a flap of tissue covering the nematocyst—the operculum—to fly open.

What is a nematocyst and what does it do?

: one of the stinging capsular organelles of the tentacle of a cnidarian (such as a box jellyfish or sea anemone) that contains a coiled, hollow, usually barbed, venomous thread which is discharged especially for catching prey and defending against enemies Each nematocyst contains a spiral-coiled thread tipped with a …

How does a nematocyst work how quick does it discharge?

When the trigger is activated, the tubule shaft of the cnidocyst is ejected and, in the case of the penetrant nematocyst, the forcefully ejected tubule penetrates the target organism. This discharge takes a few microseconds, and is able to reach accelerations of about 40,000 g.

What are the two functions of a nematocyst?

Nematocysts are stinging organelles used by members of the phylum Cnidaria (e.g., jellyfish, anemones, hydrozoans) for a variety of important functions including capturing prey and defense. Nematocysts are the fastest-known accelerating structures in the animal world.

What is nematocyst Class 9 answer?

Answer : In phylum Porifera, the tentacles bear stinging cells are called nematocyst. Nematocysts are also called cnidoblasts.

How does the hydra use the nematocyst?

The largest nematocyst has barbs on the end that anchor the prey to the tentacle from which it was fired. With a firm hold on its prey, the hydra then envelopes the organism, like a sock being pulled over a foot, and consumes it.

What is the nematocyst answer?

A nematocyst is a stinging cell found on cnidarians such as jellyfish and sea anemones.

What are the stages of a nematocyst discharge?

Citations. Nematogenesis (development of nematocysts) has a characteristic set of stages, including capsule production followed by thread production, inversion of the thread into the capsule, and hardening and closing of the capsule (Holstein, 1981).

How does hydra use the nematocyst?

Why are nematocysts important?

n. A capsule containing a harpoon-like structure used by cnidarians — jellyfish, coral, and sea anemones — for protection, capturing prey, and anchorage.

Are nematocysts stinging cells?

Cnidarians contain specialized cells known as cnidocytes (“stinging cells”) containing organelles called nematocysts (stingers). These cells are present around the mouth and tentacles, and serve to immobilize prey with toxins contained within the cells. Nematocysts contain coiled threads that may bear barbs.

Where do you find nematocyst?

nematocyst, minute, elongated, or spherical capsule produced exclusively by members of the phylum Cnidaria (e.g., jellyfish, corals, sea anemones). Several such capsules occur on the body surface.

What is the function of nematocyst?

The nematocyst is used to capture prey and may also be used for defense purposes. When it is triggered to discharge, the extremely high osmotic pressure within the nematocyst (140 atmospheres) causes water to rush into the capsule, increasing the hydrostatic pressure and expelling the thread with great force.

How does the nematocyst get its thread?

The cell’s thread is coiled under pressure and wrapped around a stinging barb. When potential prey makes contact with the tentacles of a polyp, the nematocyst cell is stimulated. This causes a flap of tissue covering the nematocyst—the operculum—to fly open.

What is the function of the nematocyst in a squid?

On the far left is a nematocyst inside its cellular capsule. The cell’s thread is coiled under pressure and wrapped around a stinging barb. When potential prey makes contact with the tentacles of a polyp, the nematocyst cell is stimulated. This causes a flap of tissue covering the nematocyst—the operculum—to fly open.

How do nematocysts inject poison?

The barbs at the end of the nematocyst are designed to stick into the polyp’s victim and inject a poisonous liquid. When subdued, the polyp’s tentacles move the prey toward its mouth and the nematocysts recoil back into their capsules.

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