Question

In Hydra, the cells which are present in ectoderm but absent in gastrodermis are

• A. Interstitial cells
• B. Nerve cells
• C. Nematoblast
• D. Epithelio-muscular

Answer 1

The correct option is C Nematoblast

The epidermis of cnidarians is the outermost layer. It contains the cnidocysts and the stinging cells which are used to capture prey and defence from predators. Cnidoblast on outermost layer produces nematocyst. Thus, nematoblasts are present in ectoderm and not in gastrodermis.
Gastrodermis is the simple innermost tissue that lines the digestive cavity of a cnidarian.
Therefore, the correct answer is option C.