Question

Please explain me the diagram???

Answer 1

Parts of a Flower:

Most flowers have both the male and female reproductive organs, but some bear either the male or the female sex organs. Such flowers are known as unisexual flowers (e.g., watermelon, cucumber, etc.) Those flowers which have both sex organs are known as bisexual flowers (e.g., Hibiscus, pea, etc.) A flower generally bears a long or short axis.

This axis has two parts—the stalk of the flower, called pedicel, and its swollen top called thalamus. The parts of a flower are arranged on the thalamus
A typical flower consists of four sets of floral parts, or whorls: calyx (sepals), corolla (petals), androecium (stamens) and gynoecium (carpels). Calyx and corolla are not directly involved in reproduction.
Androecium and gynoecium are directly concerned with sexual reproduction. The androecium is the male part of the flower and consists of stamens. The gynoecium (or pistil) consists of carpels and is the female reproductive part. The whorls are arranged on the thalamus of a flower in a definite sequence.

Calyx:

Calyx is the outermost whorl. It consists of sepals. The sepals are usually green, but sometimes they may be coloured. Calyx protects the floral whorls in the bud stage.



Corolla:

Corolla, the next inner whorl, consists of petals. Petals may be white or brightly coloured. They attract insects towards the flower and thus help in pollination. Corolla protects the reproductive whorls in the bud stage.

Androecium:

The stamens are collectively called androecium, which is the third whorl. Each stamen consists of a filament and an anther. Each anther has two chambers called pollen sacs. If you touch the stamens of a flower, a yellowish powder may come off on your hands. Anthers produce these numerous yellowish pollen grains, which contain male gametes.

Gynoecium:

The gynoecium (or pistil) is in the centre of the flower. It is the fourth whorl. It bears the female reproductive organ, called carpel. Each carpel consists of three parts—a basal swollen portion called ovary, a narrow stalk like middle portion called style and a one- to many-lobed flattened disc like sticky structure called stigma at the top of the style.

The ovary is surrounded by an outer wall. The ovary may be divided into chambers. The chambers contain ovules. Each ovule has an egg cell (female gamete).