BIOLOGY [3 marks Question Answer]

In epigynous flower, the margin of thalamus grows upward enclosing the ovary completely and getting fused with it. The other parts of the flower are above the ovary. Hence, the ovary is said to be inferior. E.g. Sunflower, flowers of cucumber.

In perigynous flower, the margin of the thalamus grows upwards to form a cup-shaped structure called a calyx tube enclosing the ovary. The ovary here is said to be half inferior. E.g. plum and rose.

In the hypogynous flower, the ovary occupies the highest position on the thalamus, while the petals, sepals, and stamens are separately inserted below the ovary. The ovary in such flowers is said to be superior. E.g. mustard and china rose.

The non-essential or accessory parts of flowers are the calyx and corolla since they do not directly participate in the process of sexual reproduction leading to the development of the seed.
1) Sepals of the calyx are green, leaf-like, and protect the inner whorls of the flower in the bud stage. They are also involved in producing food by photosynthesis.
2) Petals of the corolla are usually brightly coloured to attract insects for pollination; they also protect the inner whorls.