Parts of a Flower and Pollination | Grade 5 | ORCHIDS
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Reproduction in Plants

Concept: Parts of a Flower and Pollination

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Flower

  • 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.
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  • 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.
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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.
  • Examples: China rose.

  • Incomplete flower:The flower in which one or more whorl is absent.
  • Examples: Oak.

Unisexual and bisexual flowers:

  • Unisexual flower: The flower which has either the male or the female whorl is termed a unisexual flower.
  • Examples: Watermelon, papaya, muskmelon.

  • Bisexual Flower: The flower which contains both male and female whorls is called a bisexual flower.
  • Examples: Rose, Hibiscus, Tomato, Sunflower, Tulip.

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The different parts of the flower and their functions are discussed below.

  1. Calyx:
    • 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.
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  2. Corolla:
    • 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.
  3. Androecium
    • 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.
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  4. Gynoecium
    • 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.
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Pollination:

  • The process of transfer of pollen grains from the anther to the stigma is known as pollination.
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Types of pollination:

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Both biotic and abiotic agents carry out pollination.

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Agent of Pollination Examples
Bird Cardinal flower, trumpet vine, hibiscus
Animal Rangoon creeper
Insects Sunflower, orchids
Wind Wheat, rice, corn
Water Water lily, Hydrilla

Post-pollination events:

  • 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.
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New Words

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.
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