Question

Free central placentation found in
A. Brassicas
B. Citrus
C. Dianthus
D. Agrimonia

Answer 1

Hint: The ovary has one or more chambers or loculi. The ovary containing one or single chamber is known as a unilocular Free central placenta found in the ovary that has one chamber or unilocular. The ovules are borne in the chamber.

Complete answer: The ovules are attached to a flattened, cushion-like structure called the placenta. An ovary may have one or more placenta. The arrangement of ovules on placenta within the ovary is known as placentation. Dianthus have free central placentation. The ovules are borne on the central axis and septa are absent in the ovary. The main function of placentation is to transfer nutrients, respiratory gases, and water from maternal tissues to a growing embryo. In some instances, it also removes wastes from the embryo. Dianthus are flowering plants that belong to the family Caryophyllaceae.
i. Brassica has parietal placentation. The ovary is one-chambered (unilocular) but becomes two-chambered due to the formation of the false septum. The ovules develop on the inner wall of the ovary or on the peripheral part.
ii. Citrus fruits have axile placentation. In axile placentation, the placenta is present in the axial position and the ovules are attached to it in a multilocular ovary.
iii. Agrimonia have parietal placentation.
Hence, the correct answer is option C.

Note: There are other types of placentation that occur in plants;
i. Marginal: The placenta in marginal placentation forms a ridge along the central suture of the ovary. The ovules are borne in two alternate rows along the ridge. Example: Pea plant.
ii. Basal: The placenta develops at the base of the ovary. It has a single ovule attached to the placenta. Example: Sunflower, Marigold.