Which placentation type has ovules arranged at the margins of the ovary, as seen in peas?

• A. Marginal Placentation
• B. Placentation
• C. Axile Placentation
• D. Apocarpous

Answer: (A)

Placentation is about how ovules are attached inside the ovary. In marginal placentation, a single-carpellate ovary has ovules attached along the ventral margin, forming a single row right at the seam of the ovary. This is exactly what you see in peas, where seeds line up along the edge of the pod. This contrasts with axile placentation, where ovules are arranged around a central axis in a multi-locular ovary, or parietal placentation, where ovules attach to the inner walls of a multi-loculated ovary. The term apocarpous refers to the gynoecium having several separate carpels, which is a structural feature rather than a single pattern of ovule attachment. So the marginal, edge-on arrangement seen in peas identifies marginal placentation.