Question

The gastrovascular cavity of Hydra provides for

• A. Digestion and storage
• B. Storage and circulation
• C. Excretion and storage
• D. Digestion and circulation

Answer 1

Answer: (D)

Digestion and circulation

The gastrovascular cavity of hydra helps in digestion and circulation. It is a cavity which has a single opening surrounded by the tentacles. The cavity is lined by a diploblastic layer. The outer layer is the epidermis and the inner is gastrodermis. The cavity is also known as coelenteron.

Extracellular digestion takes place in the gastrovascular cavity. The tentacles catch the prey which is finally thrown into the cavity. The ingested food is enclosed in the food vacuole and is digested by the digestive enzymes secreted by the cells of the gastrodermis. The gastrodermis cells also help in circulation of nutrients and water as there is no well developed circulatory system.

So, the correct answer is option D.