Question 5

Sketch the reproductive parts of a flower.




A flower is modified into complex shoot to carry out sexual reproduction in the higher plants. The terminal or the end part of the axis of the flower that supports all the floral appendages: sepals, petals, stamens and carpels; is known as receptacles. These four whorls of floral appendages attached on the receptacle in which the two lower whorls (calyx and corolla) are sterile; and upper two are (androecium and gynoecium) are fertile or reproductive whorls. The floral parts are explained as below:  

1. Calyx: It is the outermost circle of a floral leaves are called calyx and the individual leaf segment is known as sepal, is green in colour. The function of sepals (Or calyx) is to protect the flower in its starting stages when the bud formation occurs.

2. Corolla: This is the second whorl of the floral leaves arise from the inner part to the calyx, and colourful parts of a flower are called corolla and the individual leaf of corolla is known as Petal. The petals lie inside the sepals and are generally coloured which attracts the insects (for pollination) and to protect the reproductive organs of the flower.

3. Androecium: The little stalk and the third whorl of the floral appendage that arises inner to corolla; individual appendage is stamen. Stamen is the male reproductive organ of the plant and consists of two parts: a filament and an anther. The stalk of stamen is called filament and the swollen top of stamen is called anther and it makes the pollen grains and stores them. Pollen grains appear to be yellow, powder like substance to us. Pollen grains contain the male gametes (or male sex cell) of the plant which is present inside a pollen grain is called ‘male nucleus of pollen grain’.

4. Gynoecium (or pistil): In the centre of a flower, there is a flask-shaped organ called pistil and it represents female reproductive organ of the plant. A pistil is constitutes of three parts: stigma, style and ovary. Ovary is the present on the base and is swollen part of the carpel that bears various ovules. Stigma lodges pollen grains. Style is the connection between ovary and stigma.

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