Question

Monocarpellary ovary, diadelphous androecium and marginal placentation occur in
A. Brassicaceae
B. Asteraceae
C. Liliaceae
D. Papilionaceae/Fabaceae

Answer 1

Flowers are an important part of a plant and are associated with the reproduction. The flowers contain the male and female part of the plant. In angiosperms, the flower consists of thalamus and floral leaves.

Complete answer: The flowers are the characteristic reproductive structures of plants and are essential in seed production. It encloses the reproductive organs or parts of the plant. The four important parts of the flower are petals, sepals, stamens and the pistil. The petals and sepals are considered as the accessory organs while the stamens and pistils are the main organs of reproduction. The stamens or the androecium group is present in the center of the whorl of flower while the pistil belongs to the gynoecium or the female part.
The gynoecium or the pistil contains an extension or the ovary. The ovary encloses the ovules. Carpels are present as leaf-like internal structures and they make up the pistils. When the ovary consists of only one carpel, the condition is termed as monocarpellary ovary.
The ovules are borne by the placenta and the arrangement of the placenta is known as placentation. The arrangement of placenta depends upon the position and orientation of the ovules and ovary. When in a condition, the placenta gives rise to a ridge that is present along the ventral suture of the ovary which bears the ovules, is known as marginal placentation.
Androecium or stamens is the male reproductive part and represents the third whorl of the flower. The stamens bear another and a filament. The variation in the fusion of the stamens give rise to various types of androecium. When the stamens are united in two bundles it is known as diadelphous stamens.
Brassicaceae are the economically important plants such as mustard. They are commonly known as mustard family. It consists of only one superior ovary, pistil with two carpels. A false septum is present and parietal placentation is present and stamens are six with two short and four long. Androecium is tetradynamous.
Asteraceae consists of basal placentation and ovary is inferior with single basal ovule while androecium is epipetalous and stamens are five. It is represented by plant species which are highly evolved and are economically important.
Liliaceae are the true monocots and represented by herbs, or woody plants. They consist of tricarpellary gynoecium and placentation is axile while the androecium is epiphyllous with six stamens. Papilionaceae also known as Fabaceae are represented by the pulses or the leguminous plants with monocarpellary ovary with marginal placentation and the androecium shows diadelphous condition.

Therefore, the correct option is option D.

Note: The pulses plants belong to the family of leguminous plants belonging to Fabaceae. The androecium in them shows diadelphous condition. The arrangement of placenta in this group is marginal with ventral sutures which bears the ovules and the ovary is monocarpellary.