AP BIOLOGY

Detailed explanation-1: -There are two basic cnidarian body shapes: a polyp form, which is attached to a surface; and an upside-down free-floating form called a medusa. Some cnidarians change form at different phases of their life cycle, while others remain in one form for their entire life.

Detailed explanation-2: -Cnidarians exhibit two major body forms, polyp or medusae. Polyps consist of a body stalk with a tubular shape with a single opening and multiple tentacles that surround this opening which serves as a mouth and anus. Polyps point upward for filter-feeding. The tentacles are covered with cnidocytes (stinging cells).

Detailed explanation-3: -Polyps have a tubular shape and are fastened at their base, with the mouth facing the water at the other end of the tube. Medusa has a bell-shaped body with hanging tentacles. Polyp does not have a manubrium. The Hydrozoa class’s Medusa has a manubrium, a tube that hangs from the bell.