Getting to Know Plants
Overview
From the home courtyard to the roadside — plants are everywhere. Some are small (grass), some are tall (trees). In this chapter, we take a close look at the parts of a plant — roots, stem, leaves and flowers — and learn how a plant makes its own food.
Typed Notes
Herb, Shrub, Tree — Identification by Size
(1) Herb — a small plant with a soft, green stem and short height: tulsi, mint, tomato, grass. (2) Shrub — medium height, stem slightly woody, branches grow from very close to the base of the stem: rose, henna, hina, jasmine. (3) Tree — very large, one thick woody stem (trunk) that gives rise to branches higher up: neem, mango, peepal, banyan. There are also creepers and climbers — those that spread along the ground (pumpkin) or climb with support (grapes, money plant).
Root — The Plant's Water Pump
The root holds the plant firmly in the ground and absorbs water and minerals from the soil. There are two types: (1) Tap root — one thick main root with smaller roots branching out from it: mustard, gram, carrot, radish, neem. (2) Fibrous root — a bunch of thin, thread-like roots similar to grass: wheat, rice, grass, onion (yes — onion has fibrous roots). Rule: plants with reticulate venation (net-like veins) have tap roots; plants with parallel venation have fibrous roots. Some roots are also used as food — carrot, radish, turnip (tap roots). Sweet potato is a modified stem that is eaten, not a true root.
Stem and Leaf — The Framework and the Kitchen
The stem is the framework of the plant — it keeps the plant upright and transports water and minerals from the roots up to the leaves, and food from the leaves to other parts of the plant. Some stems are also eaten: potato, ginger — and the banana 'tree' is actually a stem, not a real tree! The leaf is the plant's kitchen: lamina (the flat surface of the leaf), petiole (the stalk), midrib and veins (the tubes). Venation is of two types: reticulate (net-like — mango, peepal, neem) and parallel (straight and equal — grass, wheat, banana). Leaves also release water in the form of vapour — this is called transpiration.
Photosynthesis — How the Plant Makes Its Food
A plant makes its own food — that is why it is called a 'producer'. The recipe: sunlight + water (from the roots) + CO2 (from the air through tiny pores) + chlorophyll (the green pigment in the leaf). What is produced: glucose (food — energy) and oxygen (a by-product — a gift for our breathing). This process takes place only in the leaves and only in the presence of light. That is why: (1) plants always grow towards light; (2) cutting down forests means cutting off oxygen; (3) watering plants is essential — without water, the kitchen shuts down. Transpiration also happens through the leaves — water escapes as vapour — this keeps the surroundings cool and also helps pull water upward through the plant.
Key Concepts
Revision ke liye ek nazar — exam se pehle yahi padhna hai.
- 01Plants are divided into three groups: herbs (small, soft stem — tulsi, mint), shrubs (medium-sized, woody branches — rose, henna), trees (large, one thick stem — neem, mango).
- 02Roots are of two types: tap root (one thick main root — mustard, gram, carrot) and fibrous root (thin thread-like roots like grass — wheat, grass).
- 03Stem: keeps the plant standing upright, carries water and minerals from the root to the leaves, and carries food from the leaves to other parts.
- 04Leaf: lamina (surface), petiole (stalk), veins (tubes). Venation: reticulate (net-like — mango) and parallel (straight — grass).
- 05Photosynthesis: the leaf uses sunlight + water + CO2 + chlorophyll to make glucose and releases oxygen. Transpiration — water evaporating from the leaves.
Questions & Solutions
Pehle khud try karo — phir solution kholo. Yahi tariqa topper banata hai.
What is the difference between a tap root and a fibrous root? Give one example of each.
What is photosynthesis? What does it require?
What is transpiration and why is it important?
What is the difference between a herb, a shrub and a tree? Give examples.
What is venation? What are its two types?
Why is a plant called a 'producer'?
Herb, shrub, tree; tap root and fibrous root; the stem carries water and food; photosynthesis (food-making) and transpiration (water evaporation) both happen in the leaves. Venation type (reticulate or parallel) matches the root type. The flower is the reproductive part of the plant.
Chapter-end quiz
4 MCQsOption tap karo — turant pata chalega sahi ya galat, explanation ke saath.
Q1.What does a plant release during photosynthesis?
Q2.What is the green pigment in a leaf called?
Q3.What type of root does wheat have?
Q4.What is the process of water escaping from leaves as vapour called?
Mark karo — dashboard par progress dikhega.