Question

Which of the following is not found in Hydra?

• A. Epithelio-muscular cells
• B. Cnidocyte
• C. Choanocyte
• D. Nerve cells

Answer 1

Answer: (C)

Choanocyte

Hydra (phylum: Cnidaria) body wall consists of outer epidermis and inner gastrodermis separated by acellular mesoglea. Epitheliomuscular cells are present in the epidermis and serve in protection and shortening of body and tentacles by contraction. A diffuse network of nerve cells in epidermis makes nerve net that serves to conduct impulses in all directions and helps Hydra (cnidarians) to respond. Cnidocyte is the stinging cells present in the epidermis of Hydra and serve in protection and catching the prey. Choanocytes, the flagellated collar cells are the characteristic feature of phylum Porifera and serve in setting the water current that delivers food and oxygen and removes waste and carbon dioxide.

So, the correct answer is option C.