Getting to Know Plants Class 6 CBSE Science Chapter 7: Complete Notes, Explanations & Solutions

Chapter Overview: Getting to Know Plants

The chapter "Getting to Know Plants" introduces students to the fascinating world of plant diversity and structure. With approximately 250,000 plant species on Earth, understanding their basic anatomy and classification is fundamental to biology education.

What is Getting to Know Plants Class 6 About?

This chapter covers:

• Classification of plants based on size, stem type and growth patterns
• Major plant systems: shoot system and root system
• Detailed study of plant organs: roots, stems, leaves and flowers
• Functions and modifications of each plant part
• Relationship between leaf venation and root types

Learning Objectives

Students will be able to:

• Distinguish between flowering and non-flowering plants
• Classify plants into herbs, shrubs, trees, climbers and creepers
• Identify and explain functions of different plant parts
• Understand the reproductive function of flowers
• Recognize patterns in plant structures

Importance of This Chapter

Understanding plant structure is essential because:

• Plants are the primary producers in ecosystems
• They provide food, oxygen, shelter and raw materials
• Knowledge of plant parts helps in agriculture and horticulture
• It builds foundation for advanced botany concepts in higher classes

Types of Plants: Classification and Examples

Plants are classified into different categories based on their stem characteristics, height, and growth patterns.

Flowering vs Non-Flowering Plants

Flowering Plants (Angiosperms)

• Bear flowers that later develop into fruits
• Examples: Rose, Mango, Neem, Bougainvillea, Sunflower, Hibiscus
• Represent the majority of plant species

Non-Flowering Plants

• Do not produce flowers or fruits
• Reproduce through spores or other methods
• Examples: Ferns, Moss, Algae, Fungi

Classification Based on Growth Habit

A. Herbs

Definition: Plants with green, soft and tender stems.

Characteristics:

• Short in height (usually less than 1 meter)
• Stems are not woody
• Generally have short lifespan (seasonal or annual)
• Minimal branching
• Soft stem can be easily bent

Examples:

• Tomato
• Wheat
• Paddy (Rice)
• Coriander (Cilantro)
• Basil
• Chives
• Dill
• Mint

Uses: Many herbs are used as food crops, medicinal plants, and culinary ingredients.

B. Shrubs

Definition: Plants with hard stems that branch near the base (ground level).

Characteristics:

• Medium height (1-3 meters typically)
• Stem is harder than herbs but not as thick as trees
• Multiple stems arise from near the ground
• Woody stems but thinner than tree trunks
• Lives for several years

Examples:

• Rose
• Lemon
• Tulsi (Holy Basil)
• Hibiscus
• Jasmine
• Henna

Uses: Ornamental purposes, hedges, medicinal applications, and some produce edible fruits.

C. Trees

Definition: Plants with tall, hard and thick brown stems (trunks).

Characteristics:

• Tall height (usually above 3 meters, can reach over 100 meters)
• Single main stem (trunk) that is very thick and woody
• Branches appear much above the ground in upper portions
• Long lifespan (many years to centuries)
• Thick bark protects the inner stem

Examples:

• Mango
• Neem
• Banyan
• Peepal
• Coconut
• Oak
• Pine

Uses: Timber, furniture, fruits, shade, oxygen production, and ecosystem support.

D. Climbers

Definition: Plants with weak stems that need external support to climb and grow vertically.

Characteristics:

• Cannot stand upright on their own
• Climb using tendrils, hooks, or twining stems
• Grow vertically with support
• Stems are thin and flexible

Examples:

• Grapevine
• Money plant
• Pea plant
• Bitter gourd (Karela)
• Cucumber
• Bean

Mechanism: They use specialized structures called tendrils (modified stems or leaves) that coil around supports.

E. Creepers

Definition: Plants with weak stems that spread horizontally on the ground.

Characteristics:

• Cannot grow vertically
• Spread along the ground surface
• Stems root at nodes touching the soil
• Cover large ground areas

Examples:

• Pumpkin
• Watermelon
• Strawberry
• Sweet potato
• Bottle gourd

Difference from Climbers: While climbers grow upward with support, creepers grow horizontally along the ground.

Comparison Table: Herbs, Shrubs and Trees

Feature	Herbs	Shrubs	Trees
Stem Type	Soft, green, tender	Hard, branches at base	Very hard, thick trunk
Height	Short (< 1m)	Medium (1-3m)	Tall (> 3m)
Branching	Minimal	Multiple stems from base	Branches high up
Lifespan	Short (seasonal/annual)	Medium (several years)	Long (many years)
Examples	Tomato, Wheat	Rose, Lemon	Mango, Neem

Plant Systems: Organization of Plant Body

A typical flowering plant is organized into two major systems:

Shoot System

Definition: The green parts of the plant that remain above the ground.

Components:

• Stem
• Leaves
• Buds
• Flowers
• Fruits

Functions:

• Photosynthesis (food production)
• Reproduction
• Transportation of water and nutrients
• Storage (in some cases)

Root System

Definition: The non-green part of the plant that remains underground in the soil.

Components:

• Primary root
• Secondary roots
• Root hairs
• Root cap

Functions:

• Anchoring the plant firmly in soil
• Absorption of water and minerals
• Storage of food (in modified roots)
• Prevention of soil erosion

Root System: Types, Functions and Modifications

Roots are essential organs that anchor plants and absorb nutrients from the soil.

Main Functions of Roots

1. Anchorage: Roots firmly anchor the plant to the soil, preventing it from being uprooted by wind or water
2. Absorption: Root hairs absorb water and dissolved minerals from the soil
3. Conduction: Transport absorbed water and minerals to the stem
4. Storage: Store food and nutrients (in modified roots)
5. Prevention of Soil Erosion: Root networks bind soil particles together

Types of Root Systems

A. Taproot System

Definition: A root system with one main thick root growing vertically downward, giving rise to smaller lateral roots.

Characteristics:

• Single primary root (main root)
• Grows deep into the soil
• Lateral roots (side branches) emerge from the main root
• Main root is thicker than lateral roots
• Grows vertically downward

Examples:

• Neem
• Mango
• Tulsi
• Mustard
• Pea
• Carrot
• Radish
• Turnip

Advantages:

• Can reach deep water sources
• Provides very strong anchorage
• Efficient in absorbing minerals from deeper soil layers

B. Fibrous Root System

Definition: A root system consisting of many thin, thread-like roots of similar size arising from the stem base.

Characteristics:

• No main root
• Cluster of thin, fiber-like roots
• All roots are roughly equal in size
• Spread out horizontally in the upper soil layers
• Form a dense network

Examples:

• Grass
• Wheat
• Rice (Paddy)
• Maize (Corn)
• Banana
• Coconut
• Onion

Advantages:

• Excellent soil binding capacity (prevents erosion)
• Efficient absorption from upper soil layers
• Easy vegetative propagation

Difference Between Taproot and Fibrous Root

Feature	Taproot System	Fibrous Root System
Main Root	Present (thick primary root)	Absent
Structure	One main root with lateral branches	Cluster of similar thin roots
Growth Direction	Deep, vertical	Shallow, spreading
Origin	Develops from radicle	Develops from stem base
Found in	Dicot plants	Monocot plants
Examples	Mango, Neem, Mustard	Grass, Wheat, Rice

Relationship Between Leaf Venation and Root Type

Important Pattern:

• Plants with reticulate venation (net-like veins) → Taproot system
• Plants with parallel venation → Fibrous root system

This correlation exists because:

• Reticulate venation is characteristic of dicot plants (which have taproot)
• Parallel venation is characteristic of monocot plants (which have fibrous roots)

Modifications of Roots

Some plants have modified roots that perform additional functions:

Storage Roots

• Roots become swollen to store food
• Examples: Carrot, Radish, Turnip, Sweet potato, Beetroot
• These modified roots are edible and nutritious

Supporting Roots (Prop Roots)

• Additional rope-like roots grow from branches
• Hang down and penetrate the soil
• Provide extra support to heavy plants
• Examples: Banyan tree, Sugarcane
• Help the plant withstand strong winds

Breathing Roots (Pneumatophores)

• Found in plants growing in marshy areas
• Grow upward (against gravity) above water
• Help in gas exchange
• Example: Mangrove plants

Stem: Structure, Functions and Modifications

What is a Stem?

Definition: The part of the plant that rises vertically upward from the ground, bearing leaves, flowers and fruits.

In trees, the stem is called the trunk and is covered with a tough protective layer called bark.

Parts of Stem

• Nodes: Points on the stem where leaves are attached
• Internodes: Regions between two consecutive nodes
• Buds: Small structures that develop into leaves, flowers or branches
• Bark: Outer protective covering (in woody stems)

Functions of Stem

1. Support Function
   • Holds the plant upright
   • Bears the weight of branches, leaves, flowers and fruits
   • Maintains plant structure
2. Conduction of Water and Minerals
   • Transports water and minerals from roots to leaves
   • Moves through specialized vascular tissue (xylem)
   • Acts as a connecting channel
3. Conduction of Food
   • Transports prepared food from leaves to all other parts
   • Moves through phloem tissue
   • Distributes nutrients throughout the plant
4. Support for Photosynthesis
   • Positions leaves optimally to receive sunlight
   • Ensures maximum exposure for photosynthesis
   • Arranges leaves to avoid shading each other
5. Storage (in modified stems)
   • Some stems store food and water
   • Examples: Potato, Ginger

Experiment to Demonstrate Water Conduction by Stem

Objective: To show that stems conduct water upward.

Materials needed:

• A herbaceous plant with white flowers (or celery stalk)
• Water
• Red or blue food coloring
• Transparent container
• Blade

Procedure:

1. Take a healthy plant with white flowers
2. Cut the stem at the base under water
3. Add food coloring to water in the container
4. Place the cut stem in colored water
5. Leave for 4-6 hours
6. Observe the stem and flower petals

Observation:

• Colored water travels up through the stem
• Veins in leaves and petals show color
• This proves stems conduct water upward

Conclusion: Stems have specialized tissues (xylem) that conduct water and minerals from roots to all aerial parts.

Modifications of Stem

Stems are modified for various functions:

A. Storage Stems (Underground)

• Store food for the plant
• Examples:
  • Potato: Underground stem with buds (eyes)
  • Ginger: Underground stem with nodes and internodes
  • Onion: Modified into bulb
  • Turmeric: Rhizome storing food

B. Support and Climbing Stems

• Modified into tendrils for climbing
• Tendrils are thin, coiled structures
• Examples:
  • Cucumber
  • Grapevine
  • Pumpkin

C. Protective Stems

• Modified into thorns for protection
• Thorns are hard, pointed structures
• Examples:
  • Citrus plants (Lemon, Orange)
  • Bougainvillea
  • Duranta

D. Photosynthetic Stems

• Green stems that perform photosynthesis
• Found in desert plants where leaves are reduced
• Example: Cactus

Leaf: Structure, Venation, Functions and Modifications

What is a Leaf?

Definition: Leaves are lateral outgrowths of the stem, usually green, thin and flat, primarily responsible for photosynthesis.

Leaves are called the "food factories" of plants because they manufacture food through photosynthesis.

Parts of a Leaf

1. Petiole (Leaf Stalk)

• Thin stalk that attaches leaf to stem
• Provides flexibility to the leaf
• Allows leaf to adjust position for sunlight
• Contains vascular bundles

2. Lamina (Leaf Blade)

• Flat, expanded green portion of the leaf
• Main site of photosynthesis
• Green color due to chlorophyll pigment
• Maximum surface area for light absorption

3. Midrib

• Central, prominent vein running through the leaf
• Continuation of the petiole
• Provides structural support
• Main channel for transport

4. Veins

• Network of thin lines throughout the lamina
• Extensions of the midrib
• Functions:
  • Provide mechanical support to leaf blade
  • Transport water and minerals to leaf cells
  • Transport prepared food away from leaf
  • Form the "skeleton" of the leaf

5. Margin

• Outer edge of the leaf blade
• Can be smooth, serrated, or lobed

6. Apex (Leaf Tip)

• Tip or pointed end of the leaf

Types of Leaf Venation

Venation: The arrangement of veins in a leaf.

A. Reticulate Venation (Net-like)

Characteristics:

• Veins form a net-like or web-like pattern
• Veins branch repeatedly
• Lateral veins arise from midrib and branch further
• Creates a complex network

Examples:

• Peepal (Ficus religiosa)
• Mango
• Neem
• Rose
• Guava
• Tulsi

Associated Root Type: Taproot system

Found in: Dicotyledonous plants (Dicots)

B. Parallel Venation

Characteristics:

• Veins run parallel to each other
• Veins do not form a network
• Run from base to apex or across the width
• No branching pattern

Examples:

• Banana
• Grass
• Wheat
• Rice
• Maize
• Bamboo
• Coconut

Associated Root Type: Fibrous root system

Found in: Monocotyledonous plants (Monocots)

Venation and Root System Relationship

Leaf Venation	Root System	Plant Type	Examples
Reticulate (Net-like)	Taproot	Dicots	Mango, Neem, Rose
Parallel	Fibrous	Monocots	Grass, Wheat, Banana

Activity: Collect different leaves and observe their venation pattern to predict the root type of the plant.

Functions of Leaves

1. Photosynthesis (Primary Function)

• Leaves contain chlorophyll (green pigment) in chloroplasts
• Chlorophyll captures sunlight energy
• Converts carbon dioxide and water into glucose (food)
• Process: 6CO₂ + 6H₂O + Sunlight → C₆H₁₂O₆ + 6O₂
• This is why leaves are called food factories

2. Transpiration

• Definition: Loss of water vapor from leaf surface
• Occurs through tiny pores called stomata
• Benefits:
  • Helps in cooling the plant
  • Creates suction that pulls water up from roots
  • Regulates water content
  • Facilitates mineral absorption

3. Gaseous Exchange

• Stomata allow exchange of gases
• Takes in carbon dioxide (CO₂) for photosynthesis
• Releases oxygen (O₂) as a byproduct
• Takes in oxygen for respiration
• Releases carbon dioxide from respiration

4. Storage (in some modified leaves)

• Store food, water, or waste products
• Examples: Onion bulb scales, Cabbage leaves

Stomata: Tiny Pores on Leaves

Definition: Microscopic pores (openings) on the leaf surface, primarily on the underside.

Structure:

• Each stoma is surrounded by two guard cells
• Guard cells control opening and closing
• Open during day (for photosynthesis)
• Close during night (to reduce water loss)

Functions:

• Allow gaseous exchange (CO₂ in, O₂ out)
• Facilitate transpiration
• Regulate internal plant temperature

Modifications of Leaves

Leaves may be modified to perform specialized functions:

A. Support and Climbing (Tendrils)

• Leaves or leaf tips modified into coiled, thread-like structures
• Help weak-stemmed plants climb
• Examples:
  • Pea plant (leaf tip becomes tendril)
  • Glory lily (leaf tip becomes tendril)

B. Protection (Spines)

• Leaves reduced to sharp, pointed spines
• Protect plant from herbivores
• Examples:
  • Cactus (leaves modified into spines)
  • Opuntia
  • Bougainvillea (some species)

C. Water Conservation

• In desert plants, leaves become spines
• Reduces surface area to minimize water loss
• Photosynthesis performed by green stems
• Example: Cactus family plants

D. Storage

• Fleshy leaves that store food and water
• Examples:
  • Aloe vera (stores water in leaves)
  • Onion (bulb made of leaf bases)
  • Cabbage (stores food in leaves)

E. Insect Trapping (Insectivorous Plants)

• Modified to trap and digest insects
• Supplement nitrogen deficiency in poor soils
• Examples:
  • Pitcher plant (leaf modified into pitcher)
  • Venus flytrap (leaves snap shut on insects)

Flower: Structure, Parts and Reproductive Function

What is a Flower?

Definition: Flowers are the reproductive organs of flowering plants (angiosperms). They are typically colorful and attractive structures that produce seeds for plant reproduction.

Significance:

• Most colorful and attractive part of many plants
• Essential for sexual reproduction
• Develop into fruits containing seeds
• Attract pollinators (bees, butterflies, birds)

Structure of a Flower

A complete flower is attached to the plant by a pedicel (flower stalk). The pedicel swells at its tip to form the thalamus (receptacle), which bears the four main whorls of the flower.

Four Whorls of a Flower

Whorl 1: Calyx (Made of Sepals)

Sepals:

• Outermost whorl of the flower
• Usually green in color (but can be colored in some flowers)
• Protect the flower when it is a bud
• Collectively called calyx

Types:

• Polysepalous: Sepals are separate (e.g., Rose, Mustard)
• Gamosepalous: Sepals are fused/joined (e.g., Datura, Hibiscus)

Function: Protection of inner delicate parts during bud stage

Whorl 2: Corolla (Made of Petals)

Petals:

• Second whorl, located inside the calyx
• Brightly colored and attractive
• Often have pleasant fragrance
• Collectively called corolla

Types:

• Polypetalous: Petals are separate (e.g., Rose, Mustard)
• Gamopetalous: Petals are fused/joined (e.g., Datura, Petunia)

Functions:

• Attract insects, birds, and other pollinators
• Protect reproductive organs
• Facilitate pollination through color and scent

Whorl 3: Androecium (Made of Stamens) - Male Part

Stamens: The male reproductive organs of the flower.

Structure of a Stamen:

1. Filament
   • Thin, stalk-like structure
   • Supports the anther
   • Positions anther for efficient pollen dispersal
2. Anther
   • Swollen structure at the top of filament
   • Contains pollen sacs
   • Produces pollen grains
   • Pollen grains contain male gametes (reproductive cells)

Androecium: Collective term for all stamens in a flower

Function: Production and release of pollen grains for fertilization

Whorl 4: Gynoecium (Made of Carpels) - Female Part

Carpel (Pistil): The female reproductive organ of the flower.

Structure of a Carpel:

1. Stigma
   • Topmost part
   • Sticky or feathery surface
   • Receives pollen grains during pollination
   • Terminal knob-like structure
2. Style
   • Middle elongated stalk-like part
   • Connects stigma to ovary
   • Through which pollen tube grows
   • Provides passage for male gamete
3. Ovary
   • Swollen base of the carpel
   • Contains one or more ovules
   • Each ovule contains a female gamete (egg cell)
   • After fertilization, develops into fruit
   • Ovules develop into seeds

Gynoecium: Collective term for all carpels in a flower

Function: Reception of pollen, fertilization, and development of seeds and fruits

Summary Table: Parts of a Flower

Whorl	Name	Parts	Color	Function	Male/Female
1st	Calyx	Sepals	Usually green	Protection	-
2nd	Corolla	Petals	Brightly colored	Attraction	-
3rd	Androecium	Stamens (Filament + Anther)	Yellow (anther)	Pollen production	Male
4th	Gynoecium	Carpels (Stigma + Style + Ovary)	Varies	Seed formation	Female

Types of Flowers

Based on Presence of Parts:

Complete Flower:

• Contains all four whorls (sepals, petals, stamens, carpels)
• Example: Hibiscus, Rose, Mustard

Incomplete Flower:

• Lacks one or more whorls
• Example: Mulberry (no petals)

Based on Reproductive Parts:

Bisexual (Perfect/Hermaphrodite) Flower:

• Contains both stamens and carpels
• Both male and female parts present in same flower
• Examples: Hibiscus, Mustard, Rose

Unisexual (Imperfect) Flower:

• Contains either stamens or carpels, not both
• Staminate flower: Only stamens (male flower)
• Pistillate flower: Only carpels (female flower)
• Examples: Papaya, Watermelon, Cucumber

Pollination and Fertilization (Brief Overview)

Pollination: Transfer of pollen grains from anther to stigma

Fertilization: Fusion of male gamete (from pollen) with female gamete (egg in ovule)

After Fertilization:

• Ovary develops into fruit
• Ovules develop into seeds
• Petals and other parts may fall off
• This ensures reproduction and continuation of species

Importance of Flowers

1. Reproduction: Essential for sexual reproduction in plants
2. Food Source: Many flowers are edible (broccoli, cauliflower)
3. Aesthetic Value: Used for decoration and gardens
4. Economic Value: Floriculture industry, perfumes, essential oils
5. Ecological Value: Support pollinators, maintain biodiversity
6. Medicinal Value: Some flowers have therapeutic properties

NCERT Solutions & Practice Questions

NCERT Exercise Questions with Answers

Question 1: Correct the following statements and rewrite them:

(a) Stem absorbs water and minerals from the soil.

Answer: Roots absorb water and minerals from the soil.

(b) Leaves hold the plant upright.

Answer: Stem holds the plant upright.

(c) Roots conduct water to the leaves.

Answer: Stem conducts water to the leaves.

(d) The number of petals and stamens in a flower is always equal.

Answer: The number of petals and sepals in a flower is usually equal, but the number of stamens may vary.

(e) If the sepals of a flower are joined together, its petals are also joined together.

Answer: If the sepals of a flower are joined together, its petals may or may not be joined together.

(f) If the petals of a flower are joined together, then the pistil is joined to the petal.

Answer: If the petals of a flower are joined together, the pistil is not joined to the petals but remains separate.

Question 2: Draw a diagram of a flower and label its parts.

Answer: [Students should draw a labeled diagram showing: Pedicel, Receptacle/Thalamus, Sepals, Petals, Stamens (Filament and Anther), and Carpel (Stigma, Style, Ovary)]

Question 3: Can you find a plant in your house or in your neighborhood which has a long but a weak stem? Write its name. In which category would you classify it?

Answer: Money plant has a long but weak stem. It would be classified as a climber because it needs support to grow upward.

Other examples: Grapevine, Pea plant, Bean plant

Question 4: What is the function of a stem in a plant?

Answer: The main functions of stem are:

1. It holds the plant upright and supports leaves, flowers, and fruits
2. It conducts water and minerals from roots to leaves and other parts
3. It transports prepared food from leaves to other parts of the plant including roots
4. It positions leaves in such a way that they get maximum sunlight for photosynthesis
5. In some plants, stems store food (e.g., potato, ginger)

Question 5: Which of the following leaves have reticulate venation? Wheat, tulsi, maize, grass, coriander (dhania), China rose

Answer: The following have reticulate venation:

• Tulsi
• Coriander (dhania)
• China rose

(Wheat, maize, and grass have parallel venation)

Question 6: If a plant has fibrous roots, what type of venation are its leaves likely to have?

Answer: If a plant has fibrous roots, its leaves are likely to have parallel venation.

Reason: There is a correlation between root type and leaf venation:

• Fibrous roots → Parallel venation → Monocot plants
• Taproot → Reticulate venation → Dicot plants

Examples: Grass, wheat, rice, maize, banana all have fibrous roots and parallel venation.

Question 7: If a plant has leaves with reticulate venation, what kind of roots will it have?

Answer: If a plant has leaves with reticulate venation, it will have a taproot system.

Examples: Mango, neem, peepal, mustard, rose all have reticulate venation and taproot system.

Question 8: Is it possible for you to recognize the leaves without seeing them? How?

Answer: Yes, it is possible to recognize some leaves without seeing them through the following ways:

1. By touch: Different leaves have different textures
   • Some are smooth (banana)
   • Some are rough (fig)
   • Some are hairy (sunflower)
   • Some are thorny (cactus)
2. By smell: Many leaves have characteristic odors
   • Mint leaves have a strong minty smell
   • Curry leaves have a distinctive aroma
   • Coriander has its unique smell
   • Neem leaves have a bitter smell
3. By shape (through touch): Even with closed eyes, one can feel:
   • Size of the leaf
   • Serrations on margins
   • Overall shape

Question 9: Write the names of the parts of a flower.

Answer: The main parts of a flower are:

Outer Parts:

1. Pedicel (flower stalk)
2. Thalamus/Receptacle (swollen tip of pedicel)

Four Whorls: 3. Sepals (collectively called Calyx) 4. Petals (collectively called Corolla) 5. Stamens - Male parts (collectively called Androecium)

• Filament
• Anther

6. Carpels/Pistils - Female parts (collectively called Gynoecium)
   • Stigma
   • Style
   • Ovary (containing ovules)

Question 10: Which of the following plants have you seen? Of those that you have seen, which ones have flowers?

Grass, maize, wheat, chilli, tomato, tulsi, peepal, shisham, banyan, mango, jamun, guava, pomegranate, papaya, banana, lemon, sugarcane, potato, groundnut

Answer: (This is a subjective question - students should answer based on their observation)

Plants with flowers that are commonly observed:

• Chilli (small white flowers)
• Tomato (yellow flowers)
• Tulsi (small purple/white flowers)
• Mango (small yellowish flowers)
• Guava (white flowers)
• Pomegranate (red flowers)
• Papaya (yellowish flowers)
• Lemon (white fragrant flowers)
• Potato (white/purple flowers)
• Groundnut (yellow flowers)

Note: All these are flowering plants, though some flowers are not easily noticeable.

Question 11: Name the part of the plant which produces food. Name this process.

Answer:

• Part of plant: Leaves produce food for the plant
• Process: This process is called Photosynthesis

Explanation: Leaves contain a green pigment called chlorophyll which captures sunlight energy. In the presence of sunlight, carbon dioxide (from air) and water (from soil) are converted into glucose (food) and oxygen is released.

Equation: Carbon dioxide + Water + Sunlight → Glucose + Oxygen

This is why leaves are called the "food factories" of plants.

Question 12: In which part of a flower, you are likely to find the ovary?

Answer: The ovary is found at the base of the carpel (pistil), which is the female reproductive part of the flower.

Detailed location:

• The carpel consists of three parts from top to bottom: Stigma, Style, and Ovary
• The ovary is the swollen, bottommost part of the carpel
• It is located on the thalamus (receptacle)
• It contains ovules which later develop into seeds after fertilization

Very Short Answer Questions (1 Mark)

Q1. What are herbs?

A. Herbs are plants with soft, green and tender stems that are short in height.

Q2. Give two examples of shrubs.

A. Rose and Lemon

Q3. What is a taproot?

A. A taproot is a thick main root that grows vertically downward with lateral branches.

Q4. Define parallel venation.

A. When veins in a leaf run parallel to each other without forming a network, it is called parallel venation.

Q5. Name the male reproductive part of a flower.

A. Stamen (Androecium)

Q6. What is the function of roots?

A. Roots anchor the plant and absorb water and minerals from soil.

Q7. Name the green pigment present in leaves.

A. Chlorophyll

Q8. What are stomata?

A. Stomata are tiny pores on the leaf surface that help in gaseous exchange and transpiration.

Q9. What is photosynthesis?

A. Photosynthesis is the process by which green plants make food using sunlight, carbon dioxide and water.

Q10. Which part of the flower becomes a fruit?

A. Ovary

Short Answer Questions (2-3 Marks)

Q1. Differentiate between herbs and shrubs.

Answer:

Herbs	Shrubs
Have soft, green, tender stems	Have hard, woody stems
Short in height (< 1m)	Medium height (1-3m)
Do not branch much	Branch near the base
Example: Tomato, Wheat	Example: Rose, Lemon

Q2. What are climbers and creepers? Give examples.

Answer:

• Climbers: Plants with weak stems that need support to grow vertically upward. They climb using tendrils or by twining. Examples: Grapevine, Money plant, Pea.
• Creepers: Plants with weak stems that spread horizontally on the ground. Examples: Pumpkin, Watermelon, Strawberry.

Q3. Why are leaves green?

Answer: Leaves are green because they contain a green pigment called chlorophyll. Chlorophyll is present in chloroplasts within leaf cells. This pigment is essential for photosynthesis as it absorbs sunlight energy. The green color is due to the fact that chlorophyll absorbs red and blue light but reflects green light, making leaves appear green to our eyes.

Q4. Name the parts of a stamen.

Answer: A stamen has two parts:

1. Filament: The long, thin stalk that supports the anther
2. Anther: The swollen structure at the top of the filament that produces and contains pollen grains

Q5. What is the relationship between leaf venation and root type?

Answer: There is a direct relationship between leaf venation and root type:

• Plants with reticulate (net-like) venation have a taproot system (Dicots)
• Plants with parallel venation have a fibrous root system (Monocots)

This correlation helps botanists identify the root type of a plant just by observing its leaves.

Long Answer Questions (5 Marks)

Q1. Describe the structure of a flower with a labeled diagram.

Answer: A flower consists of the following parts:

1. Pedicel: Stalk that attaches flower to the plant
2. Thalamus/Receptacle: Swollen tip of pedicel bearing all flower parts

Four Whorls:

3. Calyx (Sepals): Outermost green whorl that protects the bud
4. Corolla (Petals): Brightly colored whorl that attracts pollinators
5. Androecium (Stamens): Male reproductive parts consisting of:
   • Filament: Stalk
   • Anther: Produces pollen grains
6. Gynoecium (Carpels): Female reproductive parts consisting of:
   • Stigma: Receives pollen
   • Style: Connects stigma to ovary
   • Ovary: Contains ovules that become seeds

[Students should draw and label a complete flower diagram]

Q2. Explain the functions of different parts of a leaf.

Answer:

1. Lamina (Leaf Blade):

• Main site of photosynthesis
• Large surface area for light absorption
• Contains chlorophyll for food production

2. Petiole:

• Attaches leaf to stem
• Provides flexibility to adjust leaf position
• Contains vascular bundles for transport

3. Midrib:

• Provides structural support to leaf
• Main vein for transport
• Prevents leaf from tearing

4. Veins:

• Provide mechanical support forming leaf skeleton
• Transport water and minerals to all leaf parts
• Carry prepared food away from leaf

5. Stomata (on surface):

• Tiny pores for gaseous exchange
• Allow CO₂ entry for photosynthesis
• Facilitate transpiration
• Release oxygen

Together, all these parts work coordinately to perform photosynthesis efficiently.

Q3. What are the modifications of roots? Explain with examples.

Answer: Roots undergo various modifications to perform additional functions:

1. Storage Roots:

• Become swollen to store food
• Help plant survive adverse conditions
• Examples: Carrot, Radish, Turnip, Sweet potato, Beetroot
• These are edible and nutritious

2. Supporting Roots (Prop Roots):

• Grow from branches and hang downward
• Penetrate soil and become thick
• Provide additional support to heavy plants
• Examples: Banyan tree, Sugarcane, Maize
• Help plant withstand storms

3. Breathing Roots (Pneumatophores):

• Grow upward from soil in marshy areas
• Help in respiration when soil is waterlogged
• Have pores for gas exchange
• Example: Mangrove plants

4. Climbing Roots:

• Help plants climb walls or trees
• Grow from stem nodes
• Example: Ivy, Betel

These modifications help plants adapt to different environments and survive better.

Multiple Choice Questions (MCQs)

Q1. Which of the following is a shrub?

(a) Mango
(b) Rose
(c) Tomato
(d) Grass

Answer: (b) Rose

Q2. Plants having reticulate venation have:

(a) Fibrous roots
(b) Taproot
(c) Adventitious roots
(d) No roots

Answer: (b) Taproot

Q3. The function of petals in a flower is:

(a) Protection
(b) Photosynthesis
(c) Attraction of pollinators
(d) Support

Answer: (c) Attraction of pollinators

Q4. The male reproductive part of a flower is:

(a) Sepal
(b) Petal
(c) Stamen
(d) Carpel

Answer: (c) Stamen

Q5. Which part of the plant prepares food?

(a) Root
(b) Stem
(c) Leaf
(d) Flower

Answer: (c) Leaf

Q6. The swollen part at the base of carpel is called:

(a) Stigma
(b) Style
(c) Ovary
(d) Anther

Answer: (c) Ovary

Q7. Which of these has parallel venation?

(a) Mango
(b) Neem
(c) Grass
(d) Peepal

Answer: (c) Grass

Q8. The part of stem where leaf is attached is called:

(a) Node
(b) Internode
(c) Bud
(d) Bark

Answer: (a) Node

Q9. Potato is a modified:

(a) Root
(b) Stem
(c) Leaf
(d) Flower

Answer: (b) Stem

Q10. Tiny pores on leaf surface are called:

(a) Veins
(b) Stomata
(c) Midrib
(d) Lamina

Answer: (b) Stomata

Assertion-Reason Questions

Format: (a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true

Q1.Assertion (A): Leaves are called food factories of plants.
Reason (R): Leaves prepare food by the process of photosynthesis.

Answer: (a) Both A and R are true and R is the correct explanation of A

Q2.Assertion (A): Plants with parallel venation have fibrous roots.
Reason (R): There is a correlation between venation type and root type.

Answer: (a) Both A and R are true and R is the correct explanation of A

Q3.Assertion (A): Petals are brightly colored.
Reason (R): Bright colors help in attracting pollinators like bees and butterflies.

Answer: (a) Both A and R are true and R is the correct explanation of A

Q4.Assertion (A): Roots prevent soil erosion.
Reason (R): Roots bind soil particles together.

Answer: (a) Both A and R are true and R is the correct explanation of A

Q5.Assertion (A): Cactus has spines instead of leaves.
Reason (R): This helps in reducing water loss in desert conditions.

Answer: (a) Both A and R are true and R is the correct explanation of A

Practical Activities and Experiments

Activity 1: Identifying Tap Root and Fibrous Root

Objective: To observe and distinguish between taproot and fibrous root systems.

Materials: Mustard/Gram seedlings (for taproot), Grass/Wheat seedlings (for fibrous root), Water, Tray

Procedure:

1. Carefully uproot both types of seedlings
2. Wash roots gently to remove soil
3. Observe the root structure
4. Draw and label both root systems

Observation:

• Mustard/Gram: Single thick main root with side branches (Taproot)
• Grass/Wheat: Many thin, thread-like roots (Fibrous root)

Activity 2: Leaf Venation Study

Objective: To study reticulate and parallel venation patterns.

Materials: Different leaves (Peepal, Mango, Grass, Banana), White paper, Transparent sheet

Procedure:

1. Collect various leaves
2. Place each leaf under a transparent sheet
3. Trace the vein pattern
4. Classify as reticulate or parallel
5. Predict the root type

Observation:

• Net-like pattern → Reticulate venation → Taproot
• Parallel lines → Parallel venation → Fibrous root

Activity 3: Stem Conducts Water

Objective: To demonstrate water conduction through stem.

Materials: White flower/Celery stalk, Food coloring, Water, Glass container

Procedure:

1. Take a glass of water
2. Add red or blue food color
3. Cut stem of white flower under water
4. Place stem in colored water
5. Observe after 4-6 hours

Observation:

• Colored water moves up through stem
• Veins in leaves and petals show color
• Proves stem transports water upward

Important Definitions & Key Terms

A-E

Anther: The swollen top part of the stamen that produces pollen grains containing male gametes.

Bark: The tough, protective outer covering of tree trunks and woody stems.

Bud: A small undeveloped shoot from which leaves, flowers, or branches develop.

Calyx: The collective term for all sepals of a flower; the outermost whorl.

Carpel (Pistil): The female reproductive organ of a flower consisting of stigma, style, and ovary.

Chlorophyll: The green pigment present in leaves and other green parts of plants that absorbs light energy for photosynthesis.

Climbers: Plants with weak stems that climb upward by taking support from other objects using tendrils or twining.

Corolla: The collective term for all petals of a flower; the second whorl.

Creepers: Plants with weak stems that grow along the ground surface horizontally.

Dicot: Plants having two cotyledons, reticulate venation, and taproot system.

Dicotyledonous plants: Plants whose seeds have two cotyledons (seed leaves); typically have reticulate venation and taproots.

F-M

Fertilization: The fusion of male gamete (from pollen) with female gamete (egg in ovule) to form a zygote.

Fibrous Root: A root system consisting of many thin, thread-like roots of similar size arising from the stem base without a prominent main root.

Filament: The stalk-like part of the stamen that supports the anther.

Flowering Plants: Plants that produce flowers, fruits, and seeds (Angiosperms).

Gynoecium: The collective term for all carpels/pistils in a flower; the female reproductive whorl.

Herbs: Plants with soft, green, tender stems that are short in height and have a short lifespan.

Internode: The region of the stem between two consecutive nodes.

Lamina: The broad, flat, green blade of a leaf; the main photosynthetic surface.

Lateral Roots: Secondary, side branches that arise from the main taproot.

Midrib: The central, prominent vein of a leaf that is a continuation of the petiole.

Monocot: Plants having one cotyledon, parallel venation, and fibrous root system.

Monocotyledonous plants: Plants whose seeds have one cotyledon; typically have parallel venation and fibrous roots.

N-R

Node: The point on a stem where leaves, branches, or flowers are attached.

Non-flowering Plants: Plants that do not produce flowers and reproduce by spores (e.g., ferns, mosses, algae).

Ovary: The swollen base of the carpel containing ovules; develops into fruit after fertilization.

Ovule: A structure inside the ovary that contains the female gamete (egg cell); develops into a seed after fertilization.

Parallel Venation: A vein arrangement pattern in leaves where veins run parallel to each other from base to tip without forming a network.

Pedicel: The stalk that attaches a flower to the plant stem; flower stalk.

Petals: The bright, colored parts of a flower that attract pollinators; form the corolla.

Petiole: The stalk that attaches a leaf blade to the stem; leaf stalk.

Photosynthesis: The process by which green plants make their own food using sunlight, carbon dioxide, water, and chlorophyll, releasing oxygen as a byproduct.

Pistil: Another name for carpel; the female reproductive organ of a flower.

Pollen grains: Fine, powder-like structures produced by anthers that contain male gametes.

Pollination: The transfer of pollen grains from the anther to the stigma of a flower.

Prop Roots: Thick supporting roots that grow from branches and penetrate the soil to provide additional support to large trees.

Reticulate Venation: A vein arrangement pattern in leaves where veins form a net-like or web-like network.

Root: The underground part of a plant that anchors it to the soil and absorbs water and minerals.

Root System: The underground portion of the plant consisting of roots and their branches.

S-Z

Sepals: The outermost green parts of a flower that protect the flower bud; form the calyx.

Shoot System: The above-ground portion of the plant including stem, leaves, flowers, and fruits.

Shrubs: Plants with hard, woody stems that branch near the base and are medium in height.

Stamen: The male reproductive organ of a flower consisting of filament and anther; produces pollen.

Stigma: The topmost sticky part of the carpel that receives pollen grains during pollination.

Stomata (singular: Stoma): Tiny pores on the leaf surface that allow gaseous exchange and transpiration.

Style: The elongated middle part of the carpel connecting the stigma to the ovary.

Taproot: A root system with one main thick root growing vertically downward with smaller lateral branches.

Tendril: A thread-like coiled structure (modified stem or leaf) that helps climbers to climb by coiling around supports.

Thalamus (Receptacle): The swollen tip of the pedicel on which all parts of the flower are attached.

Thorns: Hard, pointed structures (modified stems or leaves) that protect plants from herbivores.

Transpiration: The loss of water vapor from plant parts (mainly leaves) through stomata.

Trees: Tall plants with thick, hard, woody trunks (stems) that branch high above the ground.

Veins: The network of vascular bundles in leaves that provide support and transport materials.

Venation: The arrangement pattern of veins in a leaf blade.

Whorl: A circular arrangement of flower parts around the thalamus (e.g., sepals, petals, stamens, carpels).

Summary

The chapter "Getting to Know Plants" provides a comprehensive introduction to plant structure and diversity.

Important points:

1. Plant Classification: Understanding herbs, shrubs, trees, climbers, and creepers based on stem characteristics and growth habits
2. Root Systems: Distinguishing between taproot and fibrous root systems and their relationship with leaf venation
3. Stem Functions: Recognizing the stem's role in support, conduction, and sometimes storage
4. Leaf Structure: Understanding leaf parts, venation types, and the critical function of photosynthesis
5. Flower Anatomy: Identifying the four whorls of a flower and their reproductive significance
6. Plant Adaptations: Learning about modifications of roots, stems, and leaves for specialized functions

This foundational knowledge is essential for understanding more advanced concepts in botany and plant science in higher classes.