NEET BIOLOGY

Detailed explanation-1: -Cnidarians mostly have two basic body forms: swimming medusae and sessile polyps, both of which are radially symmetrical with mouths surrounded by tentacles that bear cnidocytes.

Detailed explanation-2: -A ring of feeding tentacles typically surrounds the opening. The tentacles are packed with stinging cells, which contain nematocysts that shoot out a barbed shaft to catch prey. The nematocyst can even inject toxins.

Detailed explanation-3: -Many cnidarians take two main structural forms during their life cycles, a polyp form and a medusa form. The polyp form has a body shaped like a hollow cylinder or a bag that opens and closes at the top (Fig. 3.25 A). Tentacles form a ring around a small mouth at the top of the bag.

Detailed explanation-4: -All Cnidarians have tentacles with stinging cells in their tips which are used to capture and subdue prey. In fact, the phylum name “Cnidarian” literally means “stinging creature.” The stinging cells are called cnidocytes and contain a structure called a nematocyst.

Detailed explanation-5: -The Coelenterates are aquatic, mostly marine organisms. The body is radially symmetrical and exhibit a tissue-level organization. Their mouth is surrounded by sensory tentacles, which helps to capture their prey.