Flower

The flowers are the colourful, seed-bearing parts of the plant that grows at the end of the stem. A typical flower exhibits the following structure:

Petals: These are bright, colourful and broad parts of the flower. Taken together, the petals of the flower form what is called a Corolla.

Sepal: This is the green, leaf-like structure of the flower that encloses the petals and is responsible for protecting the flower when it is in its bud form and supporting it when it is in its bloom stage.

Stamen: These are the long and slender parts of the flower that become visible upon removing the petals and sepal of a flower. Typically, a stamen consists of an anther i.e. the head of the stamen and a filament i.e. the long cream-colored stick. The stamen is also known as the male reproductive part of the plant.

Pistil: This is the innermost part of the flower, typically consisting of a stigma i.e. the head of the pistil, a style, which is the long sticky part that attaches the stigma to the ovary i.e. the small and swollen sphere at the base of the pistil. Pistil is the female reproductive part of any flower. The ovary contains small bead-like structures which are called ovules.

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Important Definitions

Stomata: These are the small microscopic pores present on the leaf through which exchange of gases and transpiration takes place.

Annuals: These are plants like wheat and maize that complete their life cycle in one season and then die. They are usually herbs.

Biennials: These are plants like carrots and radishes that complete their life cycle in two seasons.

Perennials: These are plants guava and palm that continue their life cycle for more than two seasons, i.e. they manage to re-grow every spring.

Aerial roots: These are roots of plants and trees that grow above the ground instead of under the ground as shown in the image below.

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Flower :

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A flower is the part of a plant that is responsible for making new seeds. It is often made of petals and may have an attractive scent.

Reproduction in flowering plants:

Flowering plants make new seeds inside the flower using male and female parts. Some plants, such as holly trees, may have either male or female flowers. If a tree has male flowers it will never produce any berries : they are only produced on trees with female flowers.

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Flowers, Fruits, and Seeds:

A flower is the reproductive organ of a plant. A seed is an enclosed dormant embryo of a plant. They are found in the fruits and when sown, gives rise to a new plant.

Conclusion:

  • The parts that remain under the ground (roots) form the root system.
  • The parts above the ground (stem, leaves, flowers, and fruits) form the shoot system.
  • There are two main types of root systems: tap root system and fibrous root system.
  • Roots may be modified for support, storage of food, propagation, etc.
  • Stems may be modified for support, protection, photosynthesis, food storage, and reproduction.
  • Leaves are green because they have a green pigment called chlorophyll. Green leaves manufacture their food with the help of carbon dioxide, water, and light.
  • Flower is the reproductive organ of a plant. Flowers have petals, sepals, stamens, and carpel.
  • The pollen grains need to be transferred to the stigma from the anther of the flower for pollination.
  • The seed has an embryo, which develops into a new plant under suitable conditions.

Important Terms

Climbers: A plant having thin, long and weak stem which cannot stand upright but, readily climbs up a neighboring support (like a fence) or a tree is called a climber.

Conduct: To carry a substance from one place to other is called conduct.

Creeper: A plant having thin, long and weak stem which cannot stand upright and spreads on the ground is called a creeper.

Fibrous root: Some plants do not have a main root. They have a bunch of similar roots called fibrous roots.

Herbs: Herbs are small plants having a soft and delicate stem.

Lamina: The broad green part of the leaf is called lamina.

Lateral roots: Smaller roots which arise from main roots in the taproot system are called the lateral roots.

Midrib: The thick vein in the middle of the leaf is called the midrib.

Ovules: Small bead-like structures attached in the inner wall of the ovary are called ovules.

Parallel venation: In the leaves of grass, veins are parallel to one another. This is called parallel vena­tion.

Petals: Petals are variously coloured leaf-like structures present in the flowers.

Petiole: The part of leaf by which it is attached to the stem is called petioles.

Photosynthesis: A process by which green plants make their food from sunlight, carbon dioxide and water is called photosynthesis.

Pistil: The innermost, female reproductive part of a flower is called pistil.

Reticulate venation: When veins and veinlets form a net like design in both sides of midrib, the vena­tion is called reticulate venation.

Sepal: Sepal is the outer green part which protect the inner parts of flower when it is a bud.

Shrubs: Shrubs are medium-sized plants with a hard and woody stem branching out near the base.

Stamen: Stamen is the male reproductive part of a flower.

Taproot: The root system in which a single root arises from the base of the stem, with secondary and tertiary branches is called taproot system.

Transpiration: The loss of water in the form of vapours from the stomata in leaves is called transpira­tion.

Trees: Trees are tall and big plants with a hard and thick woody stem.

Veins: Threadlike structures in leaf are called veins.