Lesson 1 of 12 · 6 min

The flower and its parts

NCERT §1.1

When Anu first spots a bud on the mango tree, the tree made its decision to flower weeks earlier. What was happening inside it before any bud could be seen?

The story this chapter follows: Anu's farm in Kerala

Anu's family farm grows paddy, with coconut palms along the bunds, a mango tree, papaya plants and a kitchen garden of peas. Every section follows one of these plants from bud to seed, and the paddy plant, whose body cells carry 2n = 24 chromosomes, keeps its numbers all the way through. The names are illustrative; the science is exact.

The lesson in notes

In short

For the plant, the flower is the organ of sexual reproduction; for people it also has aesthetic, ornamental, social, religious and cultural value.

The decision to flower is taken well before a flower is visible. Hormonal and structural changes start first, a floral primordium differentiates, inflorescences form and bear floral buds, and the buds open into flowers.

Inside the flower two whorls carry reproduction: the androecium, made of stamens, is the male part, and the gynoecium, made of one or more pistils, is the female part.

Pre-fertilisation events are everything that happens before the gametes fuse: making pollen in the anther, making the embryo sac in the ovule, and carrying pollen to the stigma.