Question

Identify the types of placentation in the image given below.

• A. A - Marginal, B - Axile, C - Parietal, D - Free central, E - Basal
• B. A - Axile, B - Marginal, C - Parietal, D - Free central, E - Basal
• C. A - Marginal, B - Axile, C - Free central, D - Parietal, E - Basal
• D. A - Axile, B - Axile, C - Free central, D - Parietal, E - Basal

Answer 1

The correct option is A A - Marginal, B - Axile, C - Parietal, D - Free central, E - Basal

The arrangement of ovules within the ovary is known as placentation. The placentation are of different types namely, marginal, axile, parietal, basal, central and free central. In marginal placentation the placenta forms a ridge along the ventral suture of the ovary and the ovules are borne on this ridge forming two rows, as in pea. When the placenta is axial and the ovules are attached to it in a multilocular ovary, the placentaion is
said to be axile, as in china rose, tomato and lemon. In parietal placentation, the ovules develop on the inner wall of the ovary or on peripheral part. Ovary is one-chambered but it becomes twochambered due to the formation of the false septum, e.g., mustard and Argemone. When the ovules are borne on central axis and septa are absent, as in Dianthus and Primrose the placentation is called free central. In basal placentation, the placenta develops at the base of ovary and a single ovule is attached to it, as in sunflower, marigold.