Learning Objectives
- Classify plants as herbs, shrubs, and trees
- Identify parts of a plant and their functions
- Understand the structure and function of roots, stems, leaves, and flowers
- Learn about transpiration and photosynthesis basics
Key Concepts
Types of Plants
Herbs: Small, soft-stemmed plants, usually shorter than a metre. Examples: mint, coriander, wheat, tulsi. They live for one or two seasons.
Shrubs: Medium-sized plants with hard but not very thick stems. They branch out near the base. Examples: rose, henna (mehndi), hibiscus.
Trees: Tall, strong plants with a thick, hard trunk. They branch out at a height above the ground. Examples: mango, neem, banyan, peepal.
Climbers: Plants with weak stems that climb up supports. Examples: money plant, grapevine, pea plant.
Creepers: Plants with weak stems that spread along the ground. Examples: pumpkin, watermelon, strawberry.
Parts of a Plant
A plant has two main systems: the root system (underground) and the shoot system (above ground). The shoot system includes the stem, leaves, flowers, and fruits.
Roots
Roots anchor the plant in the soil and absorb water and minerals. Taproot: One main root with smaller side roots (found in dicots like mango, carrot, neem). Fibrous roots: Many thin roots of similar size spreading from the base of the stem (found in monocots like grass, wheat, rice).
Stem
The stem carries water and minerals from the roots to the leaves and food from the leaves to other parts. It supports branches, leaves, flowers, and fruits. We can see this by placing a plant stem in coloured water — the colour rises through the stem.
Leaf
Leaves make food for the plant through photosynthesis using sunlight, water, and carbon dioxide. The green colour comes from chlorophyll. Leaves have a flat part called the lamina (leaf blade) and a stalk called the petiole. The pattern of veins on a leaf is called venation. Reticulate venation has a net-like pattern (found in dicots). Parallel venation has veins running parallel to each other (found in monocots). Leaves lose water through tiny pores called stomata — this process is called transpiration.
Flower
A flower has four main parts: sepals (green, protect the bud), petals (colourful, attract insects), stamens (male part with anther and filament), and pistil (female part with stigma, style, and ovary). The flower is the reproductive part of a plant.
Summary
Plants are classified as herbs, shrubs, trees, climbers, and creepers based on their size and stem. The main parts of a plant are roots, stem, leaves, and flowers, each with a specific function. Roots absorb water, stems transport it, leaves make food, and flowers help in reproduction. Understanding plant structure helps us appreciate how plants grow and survive.
Important Terms
- Herb: A small plant with a soft green stem
- Shrub: A medium-sized plant with branches near the base
- Taproot: A single main root growing downward with side branches
- Fibrous Roots: Many thin roots of similar size growing from the stem base
- Photosynthesis: The process by which leaves make food using sunlight, water, and CO₂
- Transpiration: The loss of water from leaves through stomata
- Lamina: The flat, green part of a leaf (leaf blade)
- Pistil: The female reproductive part of a flower
- Stamen: The male reproductive part of a flower
Quick Revision
- Herbs are small; shrubs are medium; trees are tall
- Taproot: one main root (dicots); Fibrous: many thin roots (monocots)
- Stem transports water upward and food downward
- Leaves make food by photosynthesis (need sunlight, water, CO₂, chlorophyll)
- Reticulate venation → taproot; Parallel venation → fibrous roots
- Flower parts: sepals, petals, stamens (male), pistil (female)
- Transpiration is loss of water from leaves through stomata