Chapter 6: Structure and Functions of Living Beings - Plants 🌱
A Comprehensive Guide for PSTET Paper-2 (Science)
Chapter Overview
| Section | Topic | PSTET Weightage | Page No. |
|:---:|:---|::---:|:---:|
| 6.1 | Parts of a Plant and Their Functions | High | 2 |
| 6.2 | Photosynthesis: The Food Making Process | High | 9 |
| 6.3 | Transpiration and its Significance | Medium | 14 |
| 6.4 | Reproduction in Plants (Sexual and Asexual) | High | 18 |
| Practice Zone | MCQs & Pedagogical Questions | - | 26 |
Learning Objectives 🎯
After studying this chapter, you will be able to:
✅ Identify and explain the functions of different plant parts—root, stem, leaf, and flower
✅ Describe the process of photosynthesis with its requirements and products
✅ Explain transpiration and its significance in plant life
✅ Differentiate between sexual and asexual reproduction in plants
✅ Understand various modes of vegetative propagation and their examples
✅ Apply pedagogical strategies to teach plant biology effectively to upper primary students
Pedagogical Link 🔗
For Teachers: This chapter directly aligns with:
Class 6 Science NCERT Chapter 7: "Getting to Know Plants"
Class 7 Science NCERT Chapter 1: "Nutrition in Plants"
Class 7 Science NCERT Chapter 12: "Reproduction in Plants"
Class 8 Science NCERT Chapter 8: "Cell—Structure and Functions"
Teaching Tips:
Conduct a "Plant Walk" around the school to observe different plant parts
Use germination experiments (soaking chana/moong seeds) to show root and shoot growth
Perform simple starch tests on leaves to demonstrate photosynthesis
Create a "Plant Parts Chart" with real specimens pressed between papers
Use hands-on activities like leaf printing and flower dissection
Section 6.1: Parts of a Plant and Their Functions 🌿
Introduction
Plants consist of several organs, each specialized to perform specific functions. Broadly, vegetative organs (root, stem, leaf) support plant growth, and reproductive organs (flower, fruit, seed) enable reproduction . The stem and leaves together comprise the shoot system, while the root forms the root system .
6.1.1 Quick Reference: Plant Parts and Their Functions
Table 6.1: Summary of Plant Parts and Functions
| Plant Part | Type | Primary Functions | Specialized Features |
|---|---|---|---|
| Root 🌱 | Vegetative | • Anchors plant in soil • Absorbs water and minerals • Stores food (in some plants) | Root hairs increase surface area; root cap protects growing tip |
| Stem 🌿 | Vegetative | • Supports leaves and flowers • Conducts water and nutrients • Sometimes stores food | Nodes bear leaves; internodes are stem segments |
| Leaf 🍃 | Vegetative | • Photosynthesis (food making) • Transpiration • Gas exchange | Stomata for gas exchange; veins for transport |
| Flower 🌸 | Reproductive | • Sexual reproduction • Produces seeds | Contains male (stamens) and female (pistil) parts |
| Fruit 🍎 | Reproductive | • Protects seeds • Helps in seed dispersal | Develops from ovary after fertilization |
| Seed 🌰 | Reproductive | • Contains embryo • Ensures next generation | Has seed coat, cotyledons, and embryo |
6.1.2 Detailed Study of Plant Parts
A. The Root System 🌱
Definition: The root is the underground part of the plant that develops from the radicle of the embryo .
Types of Root Systems:
Regions of a Root:
| Region | Location | Function |
|---|---|---|
| Root Cap | Tip of root | Protects growing point as root pushes through soil |
| Region of Meristematic Cells | Just above root cap | Cells divide continuously, causing root growth |
| Region of Elongation | Above meristematic region | Cells elongate, increasing root length |
| Region of Maturation | Upper part of root | Cells differentiate into various tissues; root hairs absorb water and minerals |
Modified Roots and Their Functions:
Functions of Roots:
Anchorage: Fix the plant firmly in the soil
Absorption: Absorb water and minerals through root hairs
Conduction: Transport absorbed materials to stem
Storage: Store food in some plants (carrot, radish)
Additional functions: Nitrogen fixation (legumes), support (banyan), respiration (mangroves)
B. The Stem 🌿
Definition: The stem is the ascending part of the plant that develops from the plumule of the embryo. It bears leaves, branches, flowers, and fruits .
Characteristics of Stem:
| Feature | Description |
|---|---|
| Nodes | Points on stem where leaves are attached |
| Internodes | Segments between two successive nodes |
| Buds | Growing points (terminal bud at tip, axillary buds in leaf axils) |
Functions of Stem:
| Function | Description |
|---|---|
| Support | Holds leaves, flowers, and fruits in position |
| Conduction | Transports water and minerals upward (xylem) and food downward (phloem) |
| Photosynthesis | Young green stems perform photosynthesis |
| Storage | Stores food in some plants (potato, sugarcane) |
| Propagation | Used in vegetative propagation (stems, runners, rhizomes) |
Modified Stems:
📝 PSTET Note: Potato is a modified stem (tuber), not a root! It has eyes (nodes) that can sprout into new plants .
C. The Leaf 🍃
Definition: Leaf is a flattened, green, lateral structure that develops from nodes and is the primary site of photosynthesis .
Parts of a Typical Leaf:
| Part | Description |
|---|---|
| Leaf Base | Part attaching leaf to stem |
| Petiole | Stalk that joins leaf to stem (may be absent in sessile leaves) |
| Lamina/Leaf Blade | Flat, expanded green part of leaf |
| Midrib | Central prominent vein |
| Veins | Network of vascular tissues running through lamina |
| Margin | Edge of leaf |
Types of Leaves:
| Type | Description | Examples | Characteristic |
|---|---|---|---|
| Simple Leaf | Lamina is undivided or has incisions not reaching midrib | Mango, Guava, Banyan | Single leaf blade |
| Compound Leaf | Lamina divided into distinct leaflets | Rose, Neem, Pea | Leaflets attached to same petiole |
Venation Patterns:
Arrangement of Leaves on Stem (Phyllotaxy):
| Type | Description | Examples |
|---|---|---|
| Alternate | One leaf at each node | Sunflower, Mustard |
| Opposite | Two leaves at each node, opposite to each other | Guava, Calotropis |
| Whorled | More than two leaves at each node | Oleander, Alstonia |
Modified Leaves:
| Modification | Function | Plant Example |
|---|---|---|
| Tendrils | Climbing | Pea, Sweet pea |
| Spines | Protection, reduce water loss | Cactus, Opuntia |
| Scale Leaves | Protect buds | Onion, Ginger |
| Insectivorous Leaves | Trap and digest insects | Pitcher plant, Venus flytrap |
| Leaflets (in compound leaves) | Appear as multiple leaves but part of one leaf | Rose, Neem |
Internal Structure of a Leaf (for PSTET advanced):
Functions of Leaf:
Photosynthesis: Prepare food using sunlight, CO₂, and water
Transpiration: Loss of excess water through stomata
Gas Exchange: Take in CO₂ and release O₂ through stomata
Storage: Store food and water in some plants (onion, aloe)
Protection: Modified into spines (cactus)
Reproduction: Some leaves produce new plants (Bryophyllum)
D. The Flower 🌸
Definition: The flower is the reproductive organ of angiosperms (flowering plants). Its function is to produce seeds through sexual reproduction .
Parts of a Typical Flower:
Detailed Structure of Male Part (Stamen):
| Component | Description | Function |
|---|---|---|
| Anther | Swollen, sac-like top part | Produces and stores pollen grains |
| Filament | Long, thin stalk | Supports anther |
Detailed Structure of Female Part (Pistil):
Types of Flowers Based on Structure:
Types of Plants Based on Flower Distribution:
| Type | Description | Examples |
|---|---|---|
| Monoecious Plants | Both male and female flowers on same plant | Maize, Cucumber, Castor |
| Dioecious Plants | Male and female flowers on different plants | Papaya, Date palm |
6.1.3 Monocot vs. Dicot Plants: Key Differences
This is an important concept for PSTET. Monocots and dicots are the two main classes of angiosperms .
Table 6.2: Differences Between Monocots and Dicots
6.1.4 Pedagogical Implications
| Teaching Strategy | Description | PSTET Focus |
|---|---|---|
| Hands-on Exploration | Students examine real plants, identify parts | Observation skills |
| Leaf Collection | Collect leaves, observe venation patterns | Classification skills |
| Flower Dissection | Carefully separate and identify flower parts | Scientific method |
| Comparison Charts | Create monocot vs. dicot comparison charts | Visual learning |
| Germination Experiment | Grow seeds in jars to observe root and shoot development | Experiential learning |
Section 6.2: Photosynthesis: The Food Making Process ☀️
Introduction
Photosynthesis (photo = light, synthesis = putting together) is the process by which green plants prepare their food using carbon dioxide, water, and sunlight, with chlorophyll as the catalyst, and release oxygen as a by-product . It is arguably the most important biochemical pathway on Earth—nearly all life depends on it .
6.2.1 The Photosynthesis Equation
Word Equation:
Carbon Dioxide + Water ────light───────→ Glucose + Oxygen
(chlorophyll)Chemical Equation:
6CO₂ + 6H₂O ────light───────→ C₆H₁₂O₆ + 6O₂ (6 molecules) (6 molecules) (chlorophyll) (1 molecule) (6 molecules)
6.2.2 Requirements for Photosynthesis
Table 6.3: Essential Requirements for Photosynthesis
6.2.3 The Two Stages of Photosynthesis
Photosynthesis occurs in two main stages :
📝 PSTET Point: The light-independent reactions are sometimes called "dark reactions," but they don't actually require darkness—they can occur in light but don't need light energy directly .
6.2.4 Site of Photosynthesis: The Chloroplast
| Part of Chloroplast | Function |
|---|---|
| Grana (stack of thylakoids) | Site of light-dependent reactions |
| Stroma (fluid-filled space) | Site of light-independent reactions (Calvin cycle) |
6.2.5 Fate of Glucose Produced
Glucose produced during photosynthesis is used in several ways:
6.2.6 Factors Affecting Photosynthesis
6.2.7 Experiments to Demonstrate Photosynthesis
Experiment 1: Starch Test on Leaf
| Step | Procedure | Purpose |
|---|---|---|
| 1 | Pluck a leaf from a plant kept in sunlight | Test leaf should have performed photosynthesis |
| 2 | Boil the leaf in water for few minutes | Kills cells and breaks cell walls |
| 3 | Boil in alcohol (ethanol) using water bath | Removes chlorophyll (leaf becomes pale white) |
| 4 | Dip leaf in hot water to soften | Makes leaf ready for iodine test |
| 5 | Add few drops of iodine solution on leaf | Tests for presence of starch |
| Result | Blue-black color appears | Confirms starch (photosynthesis occurred) |
Experiment 2: Light is Necessary for Photosynthesis
| Step | Procedure |
|---|---|
| 1 | Keep a potted plant in dark for 2-3 days (destarches it) |
| 2 | Cover a portion of a leaf with black paper strip |
| 3 | Keep plant in sunlight for 4-6 hours |
| 4 | Test both covered and uncovered parts for starch |
| Result | Uncovered part shows blue-black (starch present); covered part shows no color change (no starch) |
| Conclusion | Light is necessary for photosynthesis |
6.2.8 Pedagogical Implications
| Teaching Strategy | Description | PSTET Focus |
|---|---|---|
| Demonstration Experiments | Perform starch test and light necessity experiment | Scientific method |
| Visual Aids | Show diagrams of chloroplast and photosynthesis process | Visual learning |
| Simple Equation | Present the equation with clear explanations | Memorization aid |
| Real-life Connections | Discuss why plants need sunlight, why leaves are green | Relatable learning |
Section 6.3: Transpiration and its Significance 💧
Introduction
Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems, and flowers . It is a passive process that requires no energy expense by the plant .
6.3.1 Mechanism of Transpiration
The Cohesion-Tension Theory:
Water evaporates from mesophyll cells into air spaces inside leaf
Water vapor diffuses out through stomata
This creates a transpiration pull (negative pressure)
Water molecules are cohesive (stick together) and adhesive (stick to xylem walls)
A continuous water column is pulled up from roots through xylem
The Pathway of Water:
Soil → Root hairs → Root cortex → Xylem (roots) → Xylem (stem) → Xylem (leaf veins) → Mesophyll cells → Air spaces → Stomata → Atmosphere
6.3.2 Types of Transpiration
6.3.3 Significance of Transpiration
Table 6.4: Importance of Transpiration
6.3.4 Factors Affecting Transpiration Rate
6.3.5 Adaptations to Reduce Transpiration (Xerophytes)
Plants in dry habitats (deserts) have special adaptations to reduce water loss :
6.3.6 Transpiration vs. Evaporation
| Feature | Transpiration | Evaporation |
|---|---|---|
| Occurs in | Living plants | Any exposed surface |
| Process | Biological (through stomata) | Physical |
| Regulation | Regulated by plant (stomatal control) | Unregulated |
| Site | Mainly through stomata | Any free surface |
6.3.7 Transpiration Stream Data (Interesting Facts)
Only 0.5-3% of water absorbed by roots is used for growth and metabolism; the remaining 97-99.5% is lost through transpiration
An acre of corn gives off about 3,000-4,000 gallons (11,000-15,000 liters) of water each day
A large oak tree can transpire 40,000 gallons (150,000 liters) per year
The transpiration ratio (mass of water transpired : mass of dry matter produced) for crops is 200:1 to 1000:1
6.3.8 Simple Experiment to Demonstrate Transpiration
| Step | Procedure |
|---|---|
| 1 | Take a potted plant and water it well |
| 2 | Cover the pot with a plastic sheet to prevent soil evaporation |
| 3 | Cover the plant with a transparent polythene bag |
| 4 | Tie the bag tightly around the base of stem |
| 5 | Keep in sunlight for 1-2 hours |
| Observation | Water droplets appear inside the bag |
| Conclusion | Water is lost from leaves (transpiration) and condenses on bag |
6.3.9 Pedagogical Implications
| Teaching Strategy | Description | PSTET Focus |
|---|---|---|
| Demonstration Experiment | Show transpiration with polythene bag | Hands-on learning |
| Real-life Examples | Discuss why plants wilt in hot sun | Relatable concepts |
| Comparison Charts | Compare transpiration and evaporation | Analytical thinking |
Section 6.4: Reproduction in Plants (Sexual and Asexual) 🌰
Introduction
Plants have evolved different reproductive strategies for the continuation of their species. Some plants reproduce sexually through flowers and seeds, while others reproduce asexually through vegetative parts .
6.4.1 Types of Reproduction in Plants
| Type | Definition | Examples |
|---|---|---|
| Asexual Reproduction | Production of new plants without seeds; involves single parent | Vegetative propagation, budding, spore formation |
| Sexual Reproduction | Production of new plants through fusion of male and female gametes | Flowering plants (angiosperms, gymnosperms) |
6.4.2 Asexual Reproduction in Plants
A. Vegetative Propagation
Vegetative reproduction is a type of asexual reproduction that results in new plant individuals without seed or spore production .
Natural Methods of Vegetative Propagation:
Artificial Methods of Vegetative Propagation (Horticulture):
| Method | Description | Examples |
|---|---|---|
| Cutting | Stem or root piece planted in soil develops into new plant | Rose, Sugarcane, Grapes |
| Layering | Stem bent and covered with soil; roots develop at node | Jasmine, Strawberry |
| Grafting | Stem of desired plant (scion) joined to rooted plant (rootstock) | Mango, Apple, Rose |
| Tissue Culture | Growing plants from small tissue pieces in sterile medium | Orchids, Banana |
B. Spore Formation
Spores are tiny, microscopic reproductive units that can grow into new plants under favorable conditions.
| Plant Group | Examples |
|---|---|
| Ferns | Marsilea, Pteris |
| Mosses | Funaria |
| Fungi | Mushroom, Bread mold (Rhizopus) |
C. Budding
| Organism | Description |
|---|---|
| Yeast | Small bud forms on parent cell, grows, and detaches |
| Hydra | Bud forms on body, develops into new individual |
6.4.3 Sexual Reproduction in Angiosperms
Sexual reproduction in flowering plants involves the fusion of male and female gametes and occurs in flowers .
The Flower: Reproductive Organ
As discussed in Section 6.1, the flower contains:
Androecium (stamens): Male reproductive part
Gynoecium (pistil): Female reproductive part
A. Pollination
Pollination is the transfer of pollen grains from anther to stigma.
Agents of Pollination:
B. Fertilization
After pollination, the following events occur:
| Step | Process |
|---|---|
| 1 | Pollen grain lands on stigma and germinates |
| 2 | Pollen tube grows through style towards ovule |
| 3 | Male gametes travel through pollen tube |
| 4 | One male gamete fuses with egg cell → zygote (fertilization) |
| 5 | Zygote develops into embryo |
| 6 | Ovule develops into seed |
| 7 | Ovary develops into fruit |
📝 PSTET Note: In angiosperms, double fertilization occurs—one sperm fuses with egg (forms zygote), and the other fuses with polar nuclei (forms endosperm for nutrition) .
C. Seed and Fruit Formation
| Structure | Develops From | Becomes |
|---|---|---|
| Ovule | After fertilization | Seed |
| Ovary | After fertilization | Fruit |
| Zygote | Fertilized egg | Embryo |
| Integuments | Ovule coverings | Seed coat |
Seed Structure:
| Part | Function |
|---|---|
| Seed Coat | Protective outer covering |
| Cotyledons | Store food for embryo |
| Embryo | Baby plant (has plumule and radicle) |
| Micropyle | Small pore for water absorption during germination |
6.4.4 Comparison: Sexual vs. Asexual Reproduction
| Feature | Sexual Reproduction | Asexual Reproduction |
|---|---|---|
| Parents | Two (male and female) | Single parent |
| Gametes | Formed and fuse | Not formed |
| Offspring | Genetically different from parents | Genetically identical (clones) |
| Variation | Introduces variations | No variations |
| Evolution | Important for evolution | No role in evolution |
| Examples | Flowering plants | Potato, Ginger, Bryophyllum |
6.4.5 Seed Dispersal
Seeds are dispersed to reduce competition and colonize new areas.
6.4.6 Pedagogical Implications
| Teaching Strategy | Description | PSTET Focus |
|---|---|---|
| Germination Experiment | Grow moong/chana seeds in jar to observe seedling development | Hands-on learning |
| Vegetative Propagation Activity | Plant potato pieces, onion bulbs, ginger rhizomes to observe growth | Experiential learning |
| Seed Collection | Collect different seeds; observe dispersal adaptations | Observation skills |
| Flower Dissection | Dissect a flower (Hibiscus) to identify reproductive parts | Scientific method |
| Role Play | Students act as pollinators and flowers | Engaging multiple intelligences |
Chapter Summary: Key Points for Revision 📝
Quick Revision Table
| Topic | Key Points | Common PSTET Questions |
|---|---|---|
| Root | Tap (dicots) vs. Fibrous (monocots); Functions: anchorage, absorption, storage | Modified roots examples |
| Stem | Nodes, internodes; Modified stems: tuber (potato), rhizome (ginger), bulb (onion) | Why is potato a stem? |
| Leaf | Photosynthesis, transpiration; Reticulate (dicots) vs. Parallel (monocots) venation | Venation types in monocots/dicots |
| Flower | Sepals, petals, stamens (male), pistil (female); Complete vs. incomplete flowers | Parts of a flower |
| Monocots vs. Dicots | One cotyledon vs. two; fibrous vs. taproot; parallel vs. reticulate venation | Difference between monocot and dicot |
| Photosynthesis | 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂; Requires sunlight, chlorophyll, CO₂, water | Equation, requirements |
| Transpiration | Water loss through stomata; Cools plant, enables mineral transport | Factors affecting transpiration |
| Asexual Reproduction | Vegetative propagation (potato, ginger, onion, Bryophyllum); No seeds involved | Examples of vegetative propagation |
| Sexual Reproduction | Through flowers; Pollination → fertilization → seed and fruit formation | Pollination types, agents |
Practice Zone: PSTET-Style Questions 🎯
Content-Based MCQs
Q1. Which part of the plant is modified into a tuber in potato?
a) Root
b) Stem
c) Leaf
d) Flower
Q2. Reticulate venation is a characteristic feature of:
a) Monocot plants
b) Dicot plants
c) Both monocots and dicots
d) Gymnosperms only
Q3. The male reproductive part of a flower is called:
a) Pistil
b) Sepal
c) Stamen
d) Petal
Q4. Which of the following is necessary for photosynthesis to occur?
a) Oxygen
b) Chlorophyll
c) Nitrogen
d) Carbon monoxide
Q5. The process of water loss from plants in the form of vapor is called:
a) Evaporation
b) Transpiration
c) Condensation
d) Precipitation
Q6. Which plant reproduces through leaves?
a) Potato
b) Ginger
c) Bryophyllum
d) Onion
Q7. The transfer of pollen from anther to stigma is called:
a) Fertilization
b) Pollination
c) Germination
d) Transpiration
Q8. Which of the following is a modified stem?
a) Carrot
b) Radish
c) Ginger
d) Sweet potato
Q9. Stomata are primarily found on which part of the leaf?
a) Upper epidermis
b) Lower epidermis
c) Palisade layer
d) Spongy layer
Q10. Which gas is released during photosynthesis?
a) Carbon dioxide
b) Oxygen
c) Nitrogen
d) Hydrogen
Pedagogical MCQs
Q11. A teacher wants to demonstrate that light is necessary for photosynthesis. The best experiment would be:
a) Show a video of photosynthesis
b) Cover a portion of leaf with black paper and test for starch after sunlight exposure
c) Ask students to read about it from textbook
d) Draw diagrams on board
Q12. To teach the difference between monocot and dicot plants effectively, a teacher should:
a) Give students a list to memorize
b) Show real specimens of both types and let students observe differences
c) Only use textbook diagrams
d) Write definitions on board
Q13. A student asks, "Why does a potato have eyes?" The teacher should explain that:
a) "Potatoes are special"
b) Eyes are nodes with buds that can grow into new plants
c) "I don't know"
d) Ignore the question
Q14. While teaching transpiration, the most effective teaching aid would be:
a) Only verbal explanation
b) Demonstration with a polythene bag covering a potted plant
c) Long text passage
d) List of definitions
Q15. The best way to teach vegetative propagation is:
a) Lecture method
b) Hands-on activity where students plant potato pieces, onion bulbs, and observe growth
c) Reading textbook silently
d) Memorizing examples
Answer Key with Explanations
Pedagogical Reflection for Teachers 🤔
Think-Pair-Share Activity:
Think: How would you explain to your students that a potato is a stem and not a root, even though it grows underground?
Pair: Discuss with a colleague how you would set up a "Plant Growth Observation Corner" in your classroom with different types of vegetative propagation.
Share: Design a 15-minute activity to teach the process of photosynthesis using simple materials available at home.
NCERT Textbook Linkages 📚
| Class | Chapter | Topic |
|---|---|---|
| Class 6 | Chapter 7 | Getting to Know Plants |
| Class 7 | Chapter 1 | Nutrition in Plants |
| Class 7 | Chapter 12 | Reproduction in Plants |
| Class 8 | Chapter 8 | Cell—Structure and Functions |
| Class 9 | Chapter 5 | The Fundamental Unit of Life |
| Class 9 | Chapter 6 | Tissues |
Chapter End Notes
Key Terminology Glossary
| Term | Definition |
|---|---|
| Root | Underground part that anchors plant and absorbs water |
| Stem | Part that supports leaves and conducts water and food |
| Leaf | Photosynthetic organ of plant |
| Flower | Reproductive organ of angiosperms |
| Stamen | Male reproductive part (anther + filament) |
| Pistil | Female reproductive part (stigma + style + ovary) |
| Photosynthesis | Process of making food using light, CO₂, water, and chlorophyll |
| Transpiration | Loss of water vapor from plant parts |
| Pollination | Transfer of pollen from anther to stigma |
| Fertilization | Fusion of male and female gametes |
| Vegetative Propagation | Asexual reproduction through plant parts |
| Monocot | Plant with one cotyledon, parallel venation, fibrous roots |
| Dicot | Plant with two cotyledons, reticulate venation, taproot |
Quick Tips for PSTET Aspirants ⚡
✅ Memorize with Mnemonics:
Plant Parts: "Really Sweet Little Flowers" = Root, Stem, Leaf, Flower
Monocot Characteristics: "My Fibrous Parallel Scattered Three Pollen"
Monocot, Fibrous roots, Parallel venation, Scattered vascular bundles, Three flower parts, Pollen with one furrow
Dicot Characteristics: "Dear Taproot Reticulate Ring Five Pollen"
Dicot, Taproot, Reticulate venation, Ring of vascular bundles, Five flower parts, Pollen with three furrows
Photosynthesis Requirements: "Sunlight, Chlorophyll, CO₂, Water" = SCCW
✅ Common Exam Traps:
Potato = Stem (tuber), NOT root
Sweet potato = Root (tuberous root), NOT stem
Ginger = Stem (rhizome), NOT root
Onion = Stem (bulb), NOT root
Bryophyllum = Reproduces through LEAVES
Stomata = Mainly on LOWER surface of leaf
Photosynthesis releases OXYGEN, not CO₂
✅ Important Facts:
Starch test uses iodine solution (blue-black color indicates starch)
Destarching a plant means keeping it in dark for 2-3 days to use up stored starch
Variegated leaves have patches without chlorophyll—those patches don't photosynthesize
Guard cells control stomatal opening—they are the only epidermal cells with chloroplasts
Transpiration pull can lift water up to 100 meters in tall trees!
Answers to "Check Your Understanding"
[To be filled by student]
📝 Note for Self-Study: After completing this chapter, ensure you can:
Label all parts of a plant (root, stem, leaf, flower) with their functions
Differentiate between monocot and dicot plants with 5 points
Write the photosynthesis equation and explain all requirements
Describe the starch test experiment to prove photosynthesis
Explain transpiration and list 3 factors affecting it
Give 5 examples of vegetative propagation with plant parts
Explain pollination, fertilization, and seed formation
Differentiate between self-pollination and cross-pollination
Name 3 agents of pollination with examples
End of Chapter 6
Next Chapter: Chapter 7 - Structure and Functions of Living Beings - Animals
Topics Covered: Cell to Organism, Animal Nutrition, Respiration, Circulation, Excretion, Movement and Locomotion
