Reproduction in Plants
Concept: Parts of a Flower and Pollination
- Also called the reproductive parts of a plant, the flower is the site where the male and female gametes are formed that are involved in seed formation.
- Seeds then germinate to produce new plants, and the cycle continues.
Parts of a flower
- A flower is fixed to the main plant body with a stalk that is present below the outermost whorl.
- Parts of a flower can be classified into four whorls.
- The whorls from the outside to the inside of a flower are calyx, corolla, androecium, and gynoecium.
- Androecium and gynoecium are the male and female whorls of a flower, respectively.
Complete and incomplete flowers
Based on the presence of whorls, flowers can be classified as complete and incomplete flowers.
- Complete flower The flower which possesses all the four whorls.
- Incomplete flower:The flower in which one or more whorl is absent.
Examples: China rose.
Unisexual and bisexual flowers:
- Unisexual flower: The flower which has either the male or the female whorl is termed a unisexual flower.
- Bisexual Flower: The flower which contains both male and female whorls is called a bisexual flower.
Examples: Watermelon, papaya, muskmelon.
Examples: Rose, Hibiscus, Tomato, Sunflower, Tulip.
The different parts of the flower and their functions are discussed below.
- It is actually modified leaves and constitutes the outermost whorl of a flower.
- The calyx consists of sepals, i.e., sepals are collectively called the calyx.
- Sepals are generally green in colour and are found attached to some fruits too.
Examples: Tomato and Brinjal.
- Sepals protect the flower in the bud stage.
- It is the most attractive and colourful part of a flower.
- The other name for corolla is petals.
- The main function of the corolla is to attract insects for pollination.
- It is the male whorl of the flower.
- Stamens are collectively called androecium.
- The stamen is divided into anther and filament.
- The upper spherical part where the synthesis of pollens or the male gamete occurs is called the anther.
- The long tubular basal part which supports the anther is called the filament.
- It is the innermost whorl of a flower.
- Carpels/pistils are collectively known as gynoecium.
- A carpel can be divided into three parts—stigma, style, and ovary.
- The sticky knob-like part where the pollens settle after the process of pollination is called the stigma.
- The long cylindrical part which connects the stigma and ovary is called the style.
- The basal globular part where the ovules are found is called the ovary.
- The process of transfer of pollen grains from the anther to the stigma is known as pollination.
Types of pollination:
Both biotic and abiotic agents carry out pollination.
|Agent of Pollination||Examples|
|Bird||Cardinal flower, trumpet vine, hibiscus|
|Wind||Wheat, rice, corn|
|Water||Water lily, Hydrilla|
- The pollen, if compatible, reaches the ovary to fuse with the ovules/eggs via the process of fertilisation.
- Fertilisation leads to the development of a zygote which grows further to form seeds.
- The flower parts other than the ovary and sepals dry up and fall.
- The ovary grows and gets converted into fruit.
Biotic components: The living components found in nature.
Abiotic components:The non-living components of nature.
Fertilisation: The process which involves a sperm cell in a pollen tube that fuses with the egg cell of an ovule, resulting in the formation of a plant embryo.
Zygote: A fertilized egg cell.
Gametes: The sex cells which are involved in reproduction.
Did You Know?
- The part of the fruit we eat is actually the flower's ovary.
- The flower-producing plants are called angiosperms.
- A nectar-producing structure is present near the ovary in a flower that provides it with a characteristic smell.
- Saffron that we use to flavour a variety of food items is the dry pistil of the saffron flower.