Question

Which are the essential whorls of a flower? Why?

Answer 1

Hint: Generally, a flower has four distinct whorls:
1. Calyx
2. Corolla
3. Androecium
4. Gynoecium
The calyx comprises the sepal of the flower.
The corolla comprises the petals of the flower.
The androecium and gynoecium are the main sexual parts of a flower involved in reproduction. The androecium is the male part and gynoecium is the female part.

Complete answer:
Now the whorls of a flower are broadly categorized into two groups:
1. Essential whorls
2. Non-essential whorls
The essential whorls include the androecium and the gynoecium.
The non-essential whorls include the calyx and the corolla.
The fact that why androecium and gynoecium are tagged as the essential whorls in a flower is due to their biological roles. These are the structures that bring about reproduction in a plant. And we all know the fact that each and every living organism on this planet reproduces to maintain the continuity of the species. Without reproduction, the species would become extinct.
Another point to be noted is that these two structures- androecium and gynoecium promote sexual reproduction. Sexual reproduction helps to introduce variations in the genome and hence promote evolution of better adaptability features in the successive generations of the species that will be better to survive in the prevalent environment.
Thus, these two whorls are tagged as essential whorls in a plant.

Note:
The non-essential whorls, i.e., the calyx and the corolla are named non-essential. But this does not at all mean that these whorls are of no use. The above classification of essential and non-essential whorls is made on the basis of reproductive role.
Thus, each of the whorls have their respective functions and all the whorls are important in a flower. The calyx protects the flower in its bud form. The corolla gives protection to the androecium and the gynoecium and also attracts agents of pollination with its colorful petals and fragrances.