Define Gynoecium, Placentation, and Fruit

Gynoecium: Gynoecium is the female reproductive organ of the flower and is composed of one or more carpels. Each carpel consists of three distinct parts namely, stigma, style, and ovary. Carpels may be free (apocarpous) or united (syncarpous).

Ovary: Ovary is the enlarged basal part, above which lies the elongated tube called the style. Each ovary bears one or more ovules attached to a flattened, cushion-like placenta. After fertilization, the ovules develop into seeds and the ovary matures into a fruit.

Style: The style connects the ovary to the stigma

Stigma: The stigma is the sticky tip of the style, thus functions as a receptive surface for pollen grains.

Placentation: Placentation is defined as the arrangement of the ovules within the ovary. The main types of placentation are namely, marginal, axile, parietal, basal, central and free central.

Marginal: In this type, the placenta forms a ridge along the ventral suture of the ovary and the ovules are borne in this ridge forming two rows. E.g Pea

Axile: In this type, the ovules are attached to the multilocular ovary. E.g Tomato

Parietal: In this type, the ovules develop on the inner wall of the ovary or on the peripheral part. The ovary is one-chambered but is divided into two due to the development of false septum. E.g Mustard

Free central: Absence of separate results in the development of ovules in the central axis. E.g Primrose

Basal: In this type, the placenta develops at the base of the ovary and a single ovule is attached to it. E.g Sunflower

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

The Fruit: Fruit is a mature, ripened ovary which is a characteristic feature of the flowering plants, developed after fertilization. The fruit is said to be parthenocarpic if it is developed without fertilization of the ovary.

The structure of the fruit consists of a wall, also known as pericarp and seeds. The pericarp may be dry or fleshy. A fleshy pericarp consists of the outer wall called epicarp, middle mesocarp and inner endocarp.

A.    Mango                        B. Coconut

Gynoecium Placentation Fruit Homework Help