Question

what are the two tissue layers of a cnidarian? polyp tissue and medusa tissue outer epidermis and inner lining for digestive cavity mesoderm and inner epidermis

Explanation:

Cnidarians are diploblastic organisms. This means they have two tissue layers. The outer layer is the epidermis which provides protection. The inner layer lines the digestive cavity (gastrovascular cavity) and is involved in digestion. Polyps and medusae are body forms of cnidarians, not tissue layers. Cnidarians are diploblastic so they lack a mesoderm (which is present in triploblastic organisms).

Answer:

outer epidermis and inner lining for digestive cavity