Question

Identify the correct sequence of plants in the order of characters given below.
(a) Ovules borne along the ventral suture of unilocular ovary.
(b) Ovules develop all around the inner surface of the septa in a multilocular ovary.
(c) Ovules borne on the inner walls of ovary or on the intrusions of the wall that form incomplete partitions or false septa within the ovary.

• A. Helianthus, Brassica, Cucurbita
• B. Thespesia, Nymphaea, Brassica
• C. Abrus, Nymphaea, Brassica
• D. Abrus, Dianthus, Cucurbita

Answer 1

Answer: (C)

Abrus, Nymphaea, Brassica

Marginal is the placentation of the simple ovary of abrus (Leguminosae). The abrus ovary is developed by the union of one megasporephyll along the ventral suture. The placenta forms a ridge along this suture and the ovules are borne on this forming two rows. The ovary is one-chambered and superior. The multicarpellary flower of Nymphaea (water-lily) develops multilocular ovaries in which the whole inner walls of the chambers are lined with placental tissue so that ovules develop all round. Brassica shows parietal type of placentation, the ovary becomes falsely two-chambered by the development of a false partition wall called replum.