The Leaf

Key Notes :

Definition:

• A leaf is a part of a plant that is usually green and flat. It grows on the stem or branches of the plant.

Parts of a Leaf:

• Blade (Lamina): The flat, broad part of the leaf that captures sunlight.
• Veins: Lines on the leaf that carry water and nutrients.
• Petiole: The stalk that attaches the leaf to the stem.
• Midrib: The central vein that provides support.

Functions of a Leaf:

• Photosynthesis: The process where leaves make food for the plant using sunlight, water, and carbon dioxide.

• Respiration: Leaves help plants breathe by taking in oxygen and releasing carbon dioxide.

• Transpiration: Leaves release extra water as vapor through tiny openings called stomata.

Types of Leaves:

• Simple Leaves: Have a single blade (e.g., mango leaf).
• Compound Leaves: Have multiple small leaflets (e.g., neem leaf).

Shapes and Sizes:

• Leaves come in different shapes like oval, heart-shaped, or needle-like, and vary in size from very small to very large.

Leaf Venation:

• Parallel Venation: Veins run parallel to each other (e.g., grass).
• Reticulate Venation: Veins form a net-like pattern (e.g., peepal).

Importance of Leaves:

• They produce oxygen, which humans and animals need to breathe.
• They provide food for plants and animals.

Examples of Edible Leaves:

• Spinach, lettuce, and mint are leaves that humans eat.

Fun Fact:

• The color of a leaf changes to yellow, orange, or red in autumn due to less chlorophyll production.

Let’s practice!