CBSE Class 6 Science All Chapters Worksheet Set 02

CHAPTER - 6 CHANGES AROUND US

I. FILL IN THE BLANKS

Question 1. The changes that can be reversed are called ______________ changes.
Answer: reversible
In simple words: Changes that can be brought back to their original state are reversible changes.

Exam Tip: Remember examples like melting of ice and stretching of a rubber band.

Question 2. The changes that cannot be reversed are called ____________ changes.
Answer: irreversible
In simple words: Changes that result in a completely new substance and cannot be undone are irreversible.

Exam Tip: Examples include burning of paper and cooking of food.

Question 3. On heating, the metals _________________
Answer: expand
In simple words: Metals increase in size or volume when they absorb heat.

Exam Tip: Thermal expansion is a fundamental property of most metals.

Question 4. On cooling, the metals _________________
Answer: contract
In simple words: Metals decrease in size when they lose heat.

Exam Tip: Contraction is the opposite of expansion.

Question 5. Burning of incense stick is an ________ change.
Answer: irreversible
In simple words: Once burned, an incense stick turns into ash and smoke, which cannot be converted back.

Exam Tip: All burning processes are chemical and irreversible changes.

Question 6. On heating metal rim _______________ and fits into the wooden wheel.
Answer: expands
In simple words: Heating makes the metal rim slightly larger so it easily slips over the wooden wheel before cooling.

Exam Tip: This is a practical application of thermal expansion in daily life.

Question 7. Reversible changes are _________________ in nature.
Answer: temporary
In simple words: Reversible changes do not form permanent new substances.

Question 1. Ripening of fruit is a ( reversible / irreversible ) change.
Answer: ( irreversible )
In simple words: A ripe fruit cannot be turned back into a raw fruit.

Exam Tip: Biological growth and ripening are permanent changes.

Question 2. In ( reversible / irreversible ) change we cannot get back the original components.
Answer: ( irreversible )
In simple words: Irreversible changes destroy the original material to form something new.

Exam Tip: Focus on the inability to recover initial reactants.

Question 3. Melting of ice is a ( reversible / irreversible ) change.
Answer: ( reversible )
In simple words: Melted ice (water) can be frozen back into ice.

Exam Tip: Phase changes between solid and liquid states are usually reversible.

III. WRITE TRUE OR FALSE:

Question 1. Growing of trees is an irreversible change. _________
Answer: True
In simple words: A grown tree cannot shrink back into a tiny seed.

Exam Tip: Growth processes in living organisms are permanent.

Question 2. Formation of curd from milk is a reversible change .___________
Answer: False
In simple words: Curd cannot be converted back into fresh milk.

Exam Tip: Setting of curd involves chemical property changes.

IV. NAME THE FOLLOWING

Question 1. Name any two reversible changes.
Answer: Melting of ice and inflating a balloon.
In simple words: Changes that can be undone easily.

Exam Tip: State clear physical changes as examples.

Question 2. Name any two irreversible changes.
Answer: Burning of paper and cooking of food.
In simple words: Permanent changes that create new substances.

Exam Tip: Mention chemical or cooking processes.

Question 3. Two methods to make a change happen
Answer: Heating and applying force.
In simple words: Applying heat or physical pressure can trigger changes in objects.

Exam Tip: Common methods include heating, cooling, mixing, and pressure.

V. DISTINGUISH BETWEEN: Reversible and Irreversible changes

Question 1. Distinguish between Reversible and Irreversible changes.
Answer:
Reversible changes: Can be easily reversed to get back the original substance; no new substance is formed.
Irreversible changes: Cannot be reversed to get back the original substance; a new substance with different properties is formed.
In simple words: Reversible changes are temporary, while irreversible changes are permanent.

Exam Tip: Use a comparative definition highlighting substance formation.

VI. CLASSIFY THE FOLLOWING CHANGES INTO REVERSIBLE AND IRREVERSIBLE CHANGES:

Question 1. Crumpling of paper
Answer: Reversible change
In simple words: A crumpled paper can be straightened back out.

Exam Tip: Physical shape change without chemical composition alteration.

Question 2. Burning of paper
Answer: Irreversible change
In simple words: Burning turns paper into ash and smoke permanently.

Exam Tip: Combustion always results in irreversible transformation.

Question 3. Sawing of wood
Answer: Irreversible change
In simple words: Once wood is cut into smaller pieces or sawdust, it cannot be joined back into a single log.

Exam Tip: Cutting or breaking into pieces is generally irreversible regarding object integrity.

Question 4. Cooking of food
Answer: Irreversible change
In simple words: Cooked rice or vegetables cannot be changed back to their raw state.

Exam Tip: Cooking involves chemical reactions due to heat.

Question 5. Change of water into water vapour
Answer: Reversible change
In simple words: Water vapour can be condensed back into liquid water by cooling.

Exam Tip: Evaporation and condensation are physical phase changes.

Question 6. Ironing of clothes
Answer: Reversible change
In simple words: Ironed clothes can become crumpled again when worn or washed.

Exam Tip: Heat alters the fabric creases temporarily.

Question 7. Rusting of iron nails
Answer: Irreversible change
In simple words: Rust cannot be turned back into pure iron.

Exam Tip: Oxidation reactions are permanent.

Question 8. Bud to flower
Answer: Irreversible change
In simple words: A bloomed flower cannot turn back into a closed bud.

Exam Tip: Natural maturation is irreversible.

CHAPTER - 7 GETTING TO KNOW PLANTS

I. FILL IN THE BLANKS:

Question 1. The innermost part of a flower is called ____________________
Answer: pistil
In simple words: The pistil is the female reproductive organ situated at the center of a flower.

Exam Tip: Remember pistil contains stigma, style, and ovary.

Question 2. Plants synthesis food by the process of _____________________
Answer: photosynthesis
In simple words: Plants use sunlight, water, and carbon dioxide to make food.

Exam Tip: Chlorophyll is essential for this process.

Question 3. Plants with green tender stems are called ___________________
Answer: herbs
In simple words: Herbs are small plants with soft, green stems.

Exam Tip: Coriander and mint are common examples of herbs.

Question 4. The pattern of veins on the leaf is called ___________________
Answer: venation
In simple words: Venation is the design made by veins on a leaf blade.

Exam Tip: It can be reticulate or parallel.

Question 5. The broad green part of the leaf is called ___________________
Answer: lamina (or leaf blade)
In simple words: Lamina is the flat, expanded portion of the leaf.

Exam Tip: Most photosynthesis occurs in the lamina.

Question 6. The part of a leaf by which it is attached to the stem is called ____________
Answer: petiole
In simple words: The petiole connects the leaf blade to the stem.

Exam Tip: Not all leaves have petioles (some are sessile).

Question 7. Plants with weak stem that cannot stand upright and spread on the ground are called ______________
Answer: creepers
In simple words: Creepers spread horizontally along the ground.

Question 8. Maize plant has _____________ type of root.
Answer: fibrous
In simple words: Monocots like maize have bushy, fibrous roots instead of a main taproot.

Exam Tip: Fibrous roots accompany parallel leaf venation.

Question 9. ____________ is the stored form of food in the plants.
Answer: starch
In simple words: Plants store excess food as starch in leaves, stems, or roots.

Exam Tip: Tested using iodine solution.

Question 10. _____________ is the chemical used to indicate the presence of starch in the green leaves.
Answer: iodine solution
In simple words: Iodine turns blue-black when it reacts with starch.

Exam Tip: Standard test for carbohydrates in biology.

II. NAME THE FOLLOWING

Question 1. Any two creepers.
Answer: Pumpkin and watermelon
In simple words: Plants with weak stems spreading on the ground.

Exam Tip: Give common agricultural examples.

Question 2. Two types of root systems
Answer: Taproot system and fibrous root system
In simple words: The two major ways roots anchor plants in soil.

Exam Tip: Linked directly with seed cotyledons and leaf venation.

Question 3. The five types of plants
Answer: Herbs, shrubs, trees, creepers, and climbers
In simple words: Categories of plants based on size and stem characteristics.

Exam Tip: List all five standard classifications.

Question 4. Two types of venation
Answer: Reticulate venation and parallel venation
In simple words: Net-like and line-like vein arrangements on leaves.

Exam Tip: Reticulate is found in dicots, parallel in monocots.

Question 5. Any two climbers.
Answer: Pea plant and grapevine
In simple words: Plants that take support of neighboring structures to climb up.

Exam Tip: Climbers use tendrils for support.

Question 6. Any two shrubs
Answer: Rose and lemon
In simple words: Medium-sized plants with hard, branching stems near the base.

Exam Tip: Shrubs are bushy plants.

Question 7. Any two edible taproots
Answer: Carrot and radish
In simple words: Swollen taproots consumed as food vegetables.

Exam Tip: Turnip and beet are other examples.

III. WRITE TRUE OR FALSE:

Question 1. Ovary is a part of stem._____________
Answer: False
In simple words: Ovary is the lower part of the pistil in a flower, not the stem.

Exam Tip: Ovary develops into a fruit containing seeds.

Question 2. The stem help in holding the plant firmly in the soil.___________
Answer: False
In simple words: Roots hold the plant firmly in the soil, while stems hold branches, leaves, flowers, and fruits.

Exam Tip: Do not confuse root and stem functions.

Question 3. Leaves give out water vapour through the process of transpiration.____
Answer: True
In simple words: Transpiration is the loss of water as vapor from plant leaves.

Exam Tip: Occurs mainly through stomata.

Question 4. Weeds are unwanted plants: ________________________
Answer: True
In simple words: Unwanted plants growing alongside cultivated crops are termed weeds.

Exam Tip: Weeds compete with crops for nutrients and water.

Question 5. Plants can carry out photosynthesis without carbon dioxide._________
Answer: False
In simple words: Carbon dioxide is an essential raw material required for photosynthesis.

Exam Tip: Water, carbon dioxide, sunlight, and chlorophyll are all necessary.

Question 6. Chrysanthemum and sunflower are single flowers: ________________
Answer: False
In simple words: They are actually inflorescences made of many tiny florets appearing as a single flower.

Exam Tip: Classic textbook exception to note.

Question 7. Lemon plant is a herb: __________________________
Answer: False
In simple words: Lemon is a shrub with woody branches, not a soft-stemmed herb.

Exam Tip: Check stem rigidity to categorize plants.

IV. DEFINE THE FOLLOWING:

Question 1. Herb
Answer: Plants with green and tender stems are called herbs. They are usually short and may not have many branches.
In simple words: Small plants with soft green stems.

Exam Tip: Mention stem softness and size.

Question 2. Shrub
Answer: Plants that have hard stems, with branches arising near the base of the stem, are called shrubs.
In simple words: Bushy medium-sized plants with hard stems.

Exam Tip: Branching near the base is key.

Question 3. Tree
Answer: Very tall plants with hard and thick brown stems (trunks), having branches in the upper part much above the ground, are called trees.
In simple words: Tall, strong woody plants with a main trunk.

Exam Tip: Emphasize the single strong trunk.

Question 4. Creeper
Answer: Plants with weak stems that cannot stand upright and spread on the ground are called creepers.
In simple words: Plants that creep along the soil.

Exam Tip: Contrast with climbers.

Question 5. Climber
Answer: Plants with weak stems that take support of neighboring structures and climb up are called climbers.
In simple words: Plants that climb up using support.

Exam Tip: Mention reliance on external support.

Question 6. Venation
Answer: The design made by veins in a lamina of the leaf is called venation.
In simple words: The arrangement of veins on a leaf.

Exam Tip: Can be parallel or reticulate.

Question 7. Photosynthesis
Answer: The process by which green plants prepare their food using carbon dioxide and water in the presence of sunlight and chlorophyll is called photosynthesis.
In simple words: How plants make food using sunlight.

Exam Tip: List all four requirements (sunlight, water, carbon dioxide, chlorophyll).

Question 8. Transpiration
Answer: The loss of water in the form of water vapour from the stomata of leaves is called transpiration.
In simple words: Evaporation of water from plant leaves.

Exam Tip: Helps in cooling and pulling water up from roots.

V. DISTINGUISH BETWEEN THE FOLLOWING:

Question 1. Taproot system and fibrous root system
Answer:
Taproot system: Has one main prominent root (taproot) growing straight down from which smaller lateral roots arise. Found in plants with reticulate venation.
Fibrous root system: Does not have a main root; instead, a cluster of similar-sized thin roots arises from the base of the stem. Found in plants with parallel venation.
In simple words: Taproot has one main long root; fibrous roots are a bunch of thin roots.

Exam Tip: Always link root systems to leaf venation patterns.

Question 2. Reticular venation and parallel venation
Answer:
Reticular venation: Veins form a net-like design on both sides of the midrib. Seen in dicot plants.
Parallel venation: Veins run parallel to each other across the leaf blade. Seen in monocot plants.
In simple words: Reticular venation forms a net, while parallel venation runs in straight lines.

Exam Tip: Draw mental sketches of reticulate vs. parallel leaves.

Question 3. Roots and stem
Answer:
Roots: Underground part of the plant that absorbs water and minerals and anchors the plant firmly in the soil.
Stem: Aerial part of the plant that conducts water and minerals to leaves, and food from leaves to other parts, while holding the plant upright.
In simple words: Roots stay underground and absorb water; stems stay above ground and support leaves.

Question 4. Herbs, Shrubs and Trees
Answer:
Herbs: Short plants with soft, green, tender stems.
Shrubs: Medium-sized plants with hard, bushy stems branching near the base.
Trees: Tall plants with a thick, hard main trunk and branches high above the ground.
In simple words: Herbs are soft and small, shrubs are bushy and medium, trees are tall and woody.

Exam Tip: Differentiate based on height, stem texture, and branching pattern.

CHAPTER: 8 BODY MOVEMENTS

I. Fill in the blanks:

Question 1. The bones are moved by alternate ______________ and of __________________ of two sets of muscles.
Answer: contraction, relaxation
In simple words: Muscles pull bones by alternately shortening and lengthening.

Exam Tip: Muscles work in antagonistic pairs.

Question 2. Snails move with the help of a ______________________________.
Answer: muscular foot
In simple words: Snails glide smoothly using waves of muscular contractions in their foot.

Exam Tip: Notice the slimy mucus trail assisting friction.

Question 3. Fish swim by forming __________________________ alternately on two sides of the body.
Answer: loops (or curves)
In simple words: Fishes push water sideways by making alternating curves.

Exam Tip: Fins help maintain direction and balance.

Question 4. Cockroaches have ________________ pairs of legs and ___________ pairs of wings to fly and walk.
Answer: three, two
In simple words: Insects like cockroaches have 6 legs (3 pairs) and 4 wings (2 pairs).

Exam Tip: Remember insect anatomical counts.

Question 5. Snakes ____________________ on the ground by looping sideways.
Answer: slither
In simple words: Snakes push against the ground with loops of their body to move forward.

Exam Tip: Scales and flexible backbones enable slithering.

Question 6. Fish have ___________________ shaped body.
Answer: streamlined
In simple words: Tapered ends help fish cut through water easily.

Exam Tip: Streamlining reduces water resistance.

Question 7. The ___________________ in the earthworm’s body helps it to get good grip on the ground.
Answer: bristles (setae)
In simple words: Tiny hair-like structures anchor the earthworm during movement.

Exam Tip: Earthworms extend and contract body segments.

II. Distinguish between the following:

Question 1. Ball and socket joint / Hinge joint.
Answer:
Ball and socket joint: Allows movement in all directions (360 degrees). Example: Shoulder and hip joint.
Hinge joint: Allows back-and-forth movement in only one plane (like a door hinge). Example: Elbow and knee joint.
In simple words: Ball and socket moves all around; hinge moves back and forth like a door.

Exam Tip: Mention degree of rotation and clear skeletal examples.

Question 2. Bones / Cartilages.
Answer:
Bones: Hard, rigid skeletal structures that provide shape and support to the body.
Cartilages: Softer, more flexible skeletal tissues found at joint ends and in organs like the ear.
In simple words: Bones are hard and rigid; cartilages are soft and flexible.

Question 1. Skeleton
Answer: The framework of all the bones in the human body that provides shape, support, and protection to internal organs is called the skeleton.
In simple words: The bony framework of the body.

Exam Tip: Adult human skeleton has 206 bones.

Question 2. Ribcage
Answer: The protective cage formed by curved chest bones connected to the backbone and breastbone is called the ribcage.
In simple words: The bony cage protecting the heart and lungs.

Exam Tip: Consists of 12 pairs of ribs.

Question 3. Joint
Answer: The place where two or more bones meet in the body is called a joint.
In simple words: Connection points between bones.

Exam Tip: Joints enable body flexibility and movement.

IV. Write true or false:

Question 1. Ball and socket joint is found in the elbow:
Answer: False
In simple words: Elbow has a hinge joint, not a ball and socket joint.

Exam Tip: Elbow only bends back and forth.

Question 2. The brain is enclosed within the skull bones:
Answer: True
In simple words: The hard skull protects the delicate brain inside.

Exam Tip: Skull bones are fused and immovable except for the lower jaw.

Question 3. Cartilages are found in the bone joints:
Answer: True
In simple words: Cartilage cushions bone ends at joints to prevent wear and tear.

Exam Tip: Provides smooth cushioning surfaces.

Question 4. Lower jaw has fixed joints.
Answer: False
In simple words: The lower jaw is movable to help us talk and eat.

Exam Tip: Upper jaw is fixed; lower jaw is movable.

V. Name the following:

Question 1. The joint found in the wrist:
Answer: Pivotal joint (or sliding/gliding joint)
In simple words: Wrist joints allow sliding movements in multiple directions.

Exam Tip: Gliding joints permit bones to slide past each other.

Question 2. The medical device which show the shapes of the bones in our bodies:
Answer: X-ray machine
In simple words: X-rays pass through flesh and photograph bone structures.

Exam Tip: Used widely to detect bone fractures.

Question 3. The delicate organs protected inside the ribcage:
Answer: Heart and lungs
In simple words: Vital chest organs safely enclosed by ribs.

Question 1. Name the different types of joints in our body.
Answer: The major types of movable joints in our body are:
1. Ball and socket joint
2. Hinge joint
3. Pivotal joint
4. Fixed (immovable) joints
In simple words: Ball and socket, hinge, pivotal, and fixed joints.

Exam Tip: List all four categories clearly.

Question 2. State the functions of the skeleton in human body.
Answer:
1. It provides a definite shape and support to the body.
2. It protects delicate internal organs (e.g., skull protects brain, ribcage protects heart and lungs).
3. It helps in body movement along with muscles.
4. Bone marrow produces blood cells.
In simple words: Gives shape, protects organs, and supports movement.

Exam Tip: Mention structural support and organ protection.

Question 3. Write the adaptations of a bird.
Answer:
1. Bones are hollow and light (pneumatic bones) to reduce body weight for flight.
2. Forelimbs are modified into wings for flying.
3. Streamlined body reduces air resistance during flight.
4. Powerful flight muscles help flap wings.
5. Bodies are covered with feathers for warmth and flight control.
In simple words: Hollow bones, wings, and feathers help birds fly easily.

Exam Tip: Mention hollow bones and wing modifications.

CHAPTER: 9 THE LIVING ORGANISMS AND THEIR SURROUNDINGS

I. Fill in the blanks:

Question 1. Fish have ____________shaped body that help them to move inside water.
Answer: streamlined
In simple words: Streamlined body shape helps fish swim smoothly in water.

Exam Tip: Essential aquatic adaptation.

Question 2. Small changes that take place in the body of a living organism over a short period to overcome to some problems due to changes in the surrounding are called ________________.
Answer: acclimatization
In simple words: Short-term adjustments to new environmental conditions.

Question 3. In the mountain regions, the trees are normally ______________ shaped.
Answer: cone (pyramidal)
In simple words: Sloping conical shapes let snow and rain slide off easily.

Exam Tip: Conifers have needle-like leaves too.

Question 4. The process of producing more of their own kind by the living organisms is called ________________.
Answer: reproduction
In simple words: Giving birth to offspring to maintain species population.

Exam Tip: Essential life process for survival of species.

Question 5. Frogs have ____________feet that help them to swim in water.
Answer: webbed
In simple words: Webbed feet act like paddles in water.

Exam Tip: Amphibious adaptation for swimming.

Question 6. Dolphins and whales breathe through _______________.
Answer: blowholes
In simple words: Mammals in water come to the surface to breathe air via blowholes.

Exam Tip: They are lungs-breathing mammals, not fish.

Question 7. The process of getting rid of wastes by the living organisms is called ________________.
Answer: excretion
In simple words: Removal of metabolic waste from the body.

Exam Tip: Characteristic feature of all living beings.

Question 8. The stems of aquatic plants are long, ______________ and _____________.
Answer: hollow, light
In simple words: Hollow stems help aquatic plants float upright in water.

Exam Tip: Adaptations for floating aquatic life.

Question 9. During respiration, organisms take in ________ and give out _______.
Answer: oxygen, carbon dioxide
In simple words: Breathing in oxygen and releasing carbon dioxide.

Exam Tip: Standard aerobic respiration gas exchange.

Question 10. Exchange of gases in plants take place through the tiny pores on the leaves called ___________________.
Answer: stomata
In simple words: Microscopic pores on leaves for breathing.

Exam Tip: Guard cells control opening and closing of stomata.

II. Write true or false:

Question 1. Several kinds of plants and animals share the same habitat:
Answer: True
In simple words: Many species coexist in a single habitat.

Exam Tip: Habitats support diverse ecosystems.

Question 2. The light brown skin of the lion helps it to become a predator in the grassland:
Answer: True
In simple words: Light brown color camouflages lions in dry grassland.

Exam Tip: Camouflage helps predators hunt unnoticed.

Question 3. Desert animals like snakes and rats come during the day:
Answer: False
In simple words: Desert animals stay in deep burrows during hot days and come out at night.

Exam Tip: Nocturnal habit helps avoid intense desert heat.

Question 4. The animals which cannot adapt to changing abiotic factors of a region die out and only adapted ones survive:
Answer: True
In simple words: Only organisms suited to environmental changes survive.

Exam Tip: Core principle of natural selection and survival.

Question 5. Animals living in mountain regions have thick skin or fur:
Answer: True
In simple words: Thick fur protects mountain animals from freezing cold.

Exam Tip: Insulation against cold climates.

Question 6. Plants donot show respond to stimuli:
Answer: False
In simple words: Plants do respond to light, touch, and gravity.

Exam Tip: Example: Mimosa pudica (touch-me-not plant) drooping leaves.

Question 7. Some plants remove some of their waste products as secretions:
Answer: True
In simple words: Plants release gums, resins, and waste substances.

Exam Tip: Plant excretory products are often useful to humans.

Question 8. Camels excrete large amount of urine and their dung is wet:
Answer: False
In simple words: Camels conserve water by excreting concentrated urine and dry dung.

Exam Tip: Desert adaptation for water conservation.

Question 9. Plants carry out photosynthesis only during the daytime and respiration only at night:
Answer: False
In simple words: Plants photosynthesize in daytime sunlight, but they respire 24 hours a day.

Exam Tip: Respiration is a continuous living process.

III. Name the following:

Question 1. Two terrestrial habitats.
Answer: Deserts and forests (or grasslands)
In simple words: Land-based living environments.

Exam Tip: Terrestrial means land habitats.

Question 2. Two aquatic habitats.
Answer: Ponds and oceans
In simple words: Water-based living environments.

Exam Tip: Aquatic means water habitats (marine or freshwater).

Question 3. Two plants and two animals of mountain regions
Answer: Plants: Pine and fir; Animals: Snow leopard and mountain goat
In simple words: Cold-climate high-altitude organisms.

Exam Tip: Mention typical cold-adapted species.

Question 4. Four important abiotic factors needed for growth of plants
Answer: Sunlight, water, air (carbon dioxide), and soil (minerals)
In simple words: Non-living environmental factors essential for plants.

Exam Tip: Abiotic means non-living components of an ecosystem.

Question 5. Breathing organs of fish and earthworms.
Answer: Fish: Gills; Earthworms: Moist skin
In simple words: Gills for fish, skin for earthworms.

Exam Tip: Match organisms to respective respiratory organs.

Question 6. Any three modes of reproduction by plants.
Answer: Seeds, stem cuttings, and roots (or vegetative propagation)
In simple words: Ways plants produce new offspring.

Exam Tip: Include sexual (seeds) and asexual (vegetative) methods.

IV. Define the following:

Question 1. Adaptation
Answer: The presence of specific body features or habits which enable a plant or animal to live in a particular habitat is called adaptation.
In simple words: Special features helping organisms survive in their home environment.

Exam Tip: Adaptations develop over long periods through evolution.

Question 2. Stimuli
Answer: Changes in our surroundings that make us respond to them are called stimuli.
In simple words: Environmental changes that trigger a reaction.

Exam Tip: Examples include bright light, heat, or touch.

V. Distinguish between:

Question 1. Biotic and abiotic factors.
Answer:
Biotic factors: All the living organisms present in a habitat (plants, animals, microorganisms).
Abiotic factors: All the non-living components of a habitat (sunlight, water, air, temperature, soil).
In simple words: Biotic means living things; abiotic means non-living things.

Exam Tip: Simple prefix difference: Bio = life, A = without life.

Question 2. Terrestrial organisms and aquatic organisms.
Answer:
Terrestrial organisms: Plants and animals that live and reproduce on land.
Aquatic organisms: Plants and animals that live and reproduce in water.
In simple words: Terrestrial live on land; aquatic live in water.

Exam Tip: Contrast land vs. water habitats.

CHAPTER 10: MOTION AND MEASUREMENT OF DISTANCES

I. Mention the type of motion taking place in:

Question 1. The horse pulling a cart
Answer: Rectilinear motion (straight-line motion)
In simple words: Moving along a straight path.

Exam Tip: Cart moves straight ahead along the road.

Question 2. Earth moving around the sun in its orbit
Answer: Circular motion (or periodic motion)
In simple words: Moving in a circular path around the sun.

Exam Tip: Orbiting motion repeats periodically.

Question 3. A child playing with a top
Answer: Rotational motion
In simple words: Spinning around a fixed axis.

Exam Tip: Spinning objects exhibit rotational motion.

Question 4. A coin moving over a carom board
Answer: Rectilinear motion
In simple words: Sliding in a straight line across the board.

Exam Tip: Striking a coin creates linear sliding motion.

Question 5. A ball fixed to string
Answer: Circular motion
In simple words: Whirling in a circle tied to a string.

Exam Tip: Motion at a fixed distance around a central point.

Question 6. Motion of a branch of a tree when it shaken heavily.
Answer: Periodic (or oscillatory) motion
In simple words: Swinging back and forth.

Exam Tip: Repetitive back-and-forth movement.

II. State True (T) or False (F) against the following statements:

Question a. Handspan cannot be used to measure length all over the world.
Answer: True
In simple words: Handspans vary from person to person, so they are not a standard universal unit.

Exam Tip: Standard units are required for universal uniformity.

Question b. Ten millimeter is equal to 1 metre.
Answer: False
In simple words: 1000 millimeters make 1 metre (10 mm = 1 cm).

Exam Tip: Remember metric conversions: \(1000\text{ mm} = 1\text{ m}\).

Question c. Motion and rest are different terms of state of motion.
Answer: True
In simple words: An object can be at rest or in motion depending on the observer's frame of reference.

Exam Tip: Rest and motion are relative terms.

Question d. To measure the diameter of tree, you can use measuring tape or thread.
Answer: True
In simple words: Curved or circular circumferences and diameters are measured using flexible thread and a scale.

Exam Tip: Flexible measuring tools handle curved shapes best.

Question e. Foot is the SI unit of length.
Answer: False
In simple words: Metre is the standard SI unit of length.

Exam Tip: SI stands for International System of Units.

Question f. Length of curved line cannot be measured by metre scale directly.
Answer: True
In simple words: A straight rigid scale cannot bend along curves, so a thread is used first.

Exam Tip: Use thread along the curve, then measure the thread length on a scale.

III. Fill in the blanks:

Question 1. 1000 times the length of a metre is called ___________.
Answer: kilometre
In simple words: 1000 meters make 1 kilometre.

Exam Tip: Prefix 'kilo-' means one thousand.

Question 2. The 1/1000 part of a metre is called __________.
Answer: millimetre
In simple words: One metre divided into 1000 parts gives a millimetre.

Exam Tip: Prefix 'milli-' means one-thousandth.

Question 3. The motion which repeats itself after a fixed interval of time is called ________________ motion.
Answer: periodic
In simple words: Motion repeating at regular time intervals is periodic.

Exam Tip: Example: Pendulum swings, heartbeat.

Question 4. The motion exhibited by a violin string is _____________ motion.
Answer: oscillatory (or vibrational)
In simple words: A plucked string vibrates back and forth.

Exam Tip: Rapid back-and-forth motion produces sound.

Question 5. _____________ is the SI unit of length.
Answer: Metre
In simple words: The universally accepted unit for length is the metre.

Exam Tip: Represented by the symbol m.

Question 6. _____________ was the unit of length developed in ancient Egypt to measure length.
Answer: Cubit
In simple words: Cubit was the length from the elbow to the tip of the middle finger.

Answer: Cubit
In simple words: Non-standard ancient body measurements.

Exam Tip: Ancient units lacked universal standardization.

Question 7. In 1790, the French created a standard unit of measurement called the ____________________
Answer: metric system
In simple words: The French introduced the metric system for standard measurements.

Exam Tip: Standardized measurement systems ensure global consistency.

IV. Define the following:

Question 1. Motion
Answer: Change in position of an object with respect to its surroundings with time is called motion.
In simple words: Movement or change in position over time.

Exam Tip: Always relative to a stationary observer.

Question 2. Measurement
Answer: Comparison of an unknown quantity with some known fixed quantity is called measurement.
In simple words: Finding out the size or quantity of something using a standard unit.

Exam Tip: Measurement has two parts: a number and a unit.

V. Distinguish between:

Question 1. Periodic motion and Non-periodic motion.
Answer:
Periodic motion: Motion that repeats itself at regular intervals of time (e.g., pendulum swing).
Non-periodic motion: Motion that does not repeat at regular time intervals (e.g., a car moving on a crowded road).
In simple words: Periodic motion repeats regularly; non-periodic does not.

Exam Tip: Focus on regularity of time intervals.

Question 2. Rectilinear motion and Circular motion.
Answer:
Rectilinear motion: Motion along a straight line path (e.g., marching soldiers).
Circular motion: Motion along a circular path at a fixed distance from a central point (e.g., stone tied to a string).
In simple words: Rectilinear is straight; circular is round.

Exam Tip: Contrast path geometries.

CHAPTER: 11 LIGHT, SHADOWS AND REFLECTIONS

I. Fill in the blanks:

Question 1. _________________________ helps us to see objects with our eyes.
Answer: Light
In simple words: We cannot see anything in complete darkness without light.

Exam Tip: Light reflection enables vision.

Question 2. Objects that give out or emit light of their own are called _____________.
Answer: luminous objects
In simple words: Objects that produce their own light.

Exam Tip: Examples include the sun, stars, and lit electric bulbs.

Question 3. __________________ objects allow light to pass through them completely.
Answer: Transparent
In simple words: Materials you can see through clearly, like glass.

Exam Tip: Clear glass and clean water are transparent.

Question 4. _________________ objects do not allow the light to pass through it at all.
Answer: Opaque
In simple words: Materials through which light cannot pass at all.

Exam Tip: Wooden boards and books are opaque.

Question 5. _________________ objects allow the light to pass through them partially.
Answer: Translucent
In simple words: Materials you can see through only partially, like waxed paper.

Exam Tip: Butter paper is a classic translucent example.

Question 6. Light travels in a ______________________________.
Answer: straight line (rectilinear propagation)
In simple words: Light always travels straight and cannot bend around corners easily.

Exam Tip: Forms the basis of shadow formation.

Question 7. __________ are formed when an opaque object comes in the path of light.
Answer: Shadows
In simple words: Dark patches formed when light is blocked.

Exam Tip: Requires a light source, opaque object, and screen.

Question 8. __________________________ , _____________________ and ____________________ are essential for the formation of shadows.
Answer: Source of light, opaque object, screen
In simple words: Three essentials for shadows: light source, blocking object, and a surface.

Exam Tip: Memorize all three shadow requirements.

Question 9. A shadow cast by the heavenly bodies is called an ___________________.
Answer: eclipse
In simple words: Solar and lunar eclipses are shadows cast by celestial bodies.

Exam Tip: Astronomical shadows.

Question 10. Images formed by a pin-hole camera are __________________________
Answer: inverted (real and upside down)
In simple words: Pin-hole cameras produce upside-down images.

Exam Tip: Demonstrates rectilinear propagation of light.

Question 11. We see ________________________ of the object in the mirror.
Answer: reflection (image)
In simple words: Mirrors reflect light to form images.

Exam Tip: Reflection obeys laws of reflection.

II. Answer in one or two words:

Question 1. Give two examples of opaque objects.
Answer: Wood and book
In simple words: Objects blocking all light.

Exam Tip: Metals, stones, and thick cardboard are also opaque.

Question 2. Give two examples transparent objects.
Answer: Glass and clean water
In simple words: Objects allowing light to pass fully.

Exam Tip: Air and clear plastic are transparent.

Question 3. Give two examples of translucent objects.
Answer: Butter paper and frosted glass
In simple words: Objects letting light pass partially.

Exam Tip: Oiled paper is another good example.

Question 4. Give two examples of luminous objects.
Answer: Sun and glowing bulb
In simple words: Objects producing their own light.

Exam Tip: Stars and fireflies are luminous.

Question 5. Give two examples of non-luminous objects.
Answer: Moon and chair
In simple words: Objects that do not emit their own light.

Exam Tip: Moon shines by reflecting sunlight, making it non-luminous.

III. Choose the correct Answer:

Question 1. [Mirror/glass] helps to change the direction of light that falls on it.
Answer: Mirror
In simple words: Mirrors reflect and redirect light beams.

Exam Tip: Reflection changes light direction.

Question 2. Images are [ same / different] from the shadow.
Answer: different
In simple words: Images show colors and details, whereas shadows are just dark outlines.

Exam Tip: Shadows only show shapes, not details or colors.

Question 3. Torch bulb is [ luminous / non-luminous] object.
Answer: luminous
In simple words: A glowing bulb emits its own light.

Question 4. [Opaque/Transparent] objects cast shadows.
Answer: Opaque
In simple words: Only opaque objects block light to cast dark shadows.

Exam Tip: Transparent objects do not form shadows.

Question 5. Coloured objects form [coloured / dark/white] shadows.
Answer: dark
In simple words: All shadows are dark regardless of object color.

Exam Tip: Shadows are absence of light, hence always black/dark.

Question 6. Images are formed because of [reflection of light / obstruction of light].
Answer: reflection of light
In simple words: Mirrors form images via reflection.

Exam Tip: Obstruction forms shadows, reflection forms images.

IV. Answer the following questions:

Question 1. How are shadows formed?
Answer: Shadows are formed when an opaque object comes in the path of light, blocking the light rays from passing through and creating a dark patch on a screen behind it.
In simple words: Shadows form when light is blocked by an opaque object.

Exam Tip: Mention light blocking and a screen.

Question 2. What is meant by reflection of light?
Answer: The bouncing back of light rays from a shiny or polished surface into the same medium is called reflection of light.
In simple words: Light bouncing off shiny surfaces like a mirror.

Exam Tip: Mirrors provide regular reflection.

Question 3. Explain with the help of an activity that light travels in a straight line.
Answer: Take three cardboard sheets with a small hole in the center of each. Place them upright in a straight line one behind another so that you can see through all three holes from one end. Place a lighted candle on the other side. You can see the candle flame clearly. Now, disturb one cardboard slightly so the holes are not in a straight line; the candle flame is no longer visible. This proves light travels in a straight line.
In simple words: Looking through aligned holes lets you see a candle; moving one hole blocks the light, proving light travels straight.

Exam Tip: Classic pinhole/cardboard experiment for rectilinear propagation.

V. Define:

Question 1. Opaque objects
Answer: Objects that do not allow light to pass through them at all are called opaque objects.
In simple words: Objects through which we cannot see anything.

Exam Tip: Casts clear shadows.

Question 2. Shadows
Answer: Dark patches formed on a screen when opaque objects block the path of light are called shadows.
In simple words: Dark silhouettes behind blocked light.

Exam Tip: Always requires a light source and obstacle.

Question 3. Reflection of light
Answer: The bouncing back of light rays from a polished surface is called reflection of light.
In simple words: Light bouncing off surfaces.

Exam Tip: Essential for seeing non-luminous objects.

VI. Distinguish between:

Question 1. Transparent and translucent objects
Answer:
Transparent objects: Allow light to pass through them completely; objects can be seen clearly through them (e.g., glass).
Translucent objects: Allow light to pass through them partially; objects cannot be seen clearly through them (e.g., butter paper).
In simple words: Transparent lets all light through clearly; translucent lets some light through blurred.

Exam Tip: Compare clarity of vision through them.

Question 2. Luminous and non-luminous objects.
Answer:
Luminous objects: Emit their own light (e.g., sun, stars, torch).
Non-luminous objects: Do not emit their own light; they shine by reflecting light from other sources (e.g., moon, table, chair).
In simple words: Luminous make their own light; non-luminous do not.

Exam Tip: The moon is a common trick question (it is non-luminous).

CHAPTER 12: ELECTRICITY AND CIRCUITS

I. Fill in the blanks:

Question 1. An electric ______________ is a continuous path along which the current flows.
Answer: circuit
In simple words: Complete loop for electricity to flow.

Exam Tip: Must be closed for current flow.

Question 2. A circuit in which electricity does not flow is called an ______________ circuit.
Answer: open (or incomplete)
In simple words: Broken pathway where electricity stops flowing.

Exam Tip: Switches open circuits to stop electrical flow.

Question 3. The source of electricity in an electric cell are the ______________ stored in it.
Answer: chemicals
In simple words: Cells generate electricity from stored chemicals.

Exam Tip: Chemical energy converts to electrical energy.

Question 4. Rubber is a____________ conductor of electricity.
Answer: bad (or insulator)
In simple words: Rubber does not allow electricity to pass through.

Exam Tip: Used for safety insulation on wires and tools.

Question 5. A device that is used to break or complete an electric circuit is called ______________.
Answer: switch
In simple words: Control device to turn appliances on or off.

Exam Tip: Connects or disconnects the circuit loop.

Question 6. An electric cell has ______________ terminals.
Answer: two (+ and -)
In simple words: Every cell has a positive and a negative terminal.

Question 7. If the filament of a bulb breaks, it is said to be ______________.
Answer: fused
In simple words: A broken filament stops electricity flow, so the bulb does not glow.

Exam Tip: Fused bulbs have broken inner wire loops.

Question 8. An electric circuit said to be ______________ when current flows through it.
Answer: closed (complete)
In simple words: Closed circuit allows current to pass through completely.

Exam Tip: Closed = ON, Open = OFF.

Question 9. Electric current flows from ______________ terminal to ____________ terminal of cell in the circuit.
Answer: positive (+), negative (-)
In simple words: Conventional current flows from positive to negative terminal.

Question 10. In an electric cell, the metal cap is the _________ terminal while the metal disc is the ______________ terminal.
Answer: positive (+), negative (-)
In simple words: Cap is positive, flat base disc is negative.

Exam Tip: Physical identification of dry cell terminals.

II. Name the following:

Question 1. Any two sources of electricity
Answer: Electric cell and electric generator (or battery / solar cell)
In simple words: Devices providing electrical power.

Exam Tip: Cells and generators are common sources.

Question 2. The thin wire in a bulb which gives out light
Answer: Filament
In simple words: The tiny glowing tungsten wire inside a bulb.

Exam Tip: Made of tungsten metal due to high melting point.

Question 3. The arrangement of providing a complete path for electricity to pass between two terminals of the electric cell
Answer: Electric circuit
In simple words: Complete conductive loop.

Exam Tip: Closed path for current.

Question 4. Sometimes an electric bulb does not glow even when the electric switch is ‘ON’ then we say that the bulb is ____________________
Answer: fused
In simple words: Bulb with broken filament does not glow.

Exam Tip: Check filament continuity.

Question 5. An electric appliance which makes or breaks an electric circuit
Answer: Electric switch
In simple words: Switch controls circuit continuity.

Exam Tip: Essential control component.

III. Write True (T) or False (F):

Question a. Electric current can flow through metals.
Answer: True
In simple words: Metals are good conductors of electricity.

Exam Tip: Copper, aluminum, and iron conduct electricity well.

Question b. Instead of metal wires, a jute string can be used to make a circuit.
Answer: False
In simple words: Jute is an insulator and cannot conduct electricity.

Exam Tip: Only conductors work in electrical circuits.

Question c. Electric current can pass through a sheet of thermocol.
Answer: False
In simple words: Thermocol is an insulator.

Exam Tip: Insulators block current.

Question d. When current flows through a circuit, the circuit is called open circuit.
Answer: False
In simple words: It is called a closed circuit when current flows.

Exam Tip: Open circuit stops current flow.

Question e. Electric current can easily flow through Copper.
Answer: True
In simple words: Copper is an excellent conductor used in electrical wires.

Question f. When an electric circuit is closed, the electric current stops flowing through it.
Answer: False
In simple words: Current flows continuously when a circuit is closed.

Exam Tip: Closed circuit means active current flow.

IV. Tick the correct answer:

Question 1. Choose a good conductor from the following materials.
a) Pencil lead b) Thermocol c) Wooden block
Answer: (a) Pencil lead
In simple words: Graphite (pencil lead) conducts electricity.

Exam Tip: Graphite is a non-metal that conducts electricity.

Question 2. Which of the following is not a good conductor of electricity?
a) Mercury b) Copper c) Plastic d) Aluminum foil
Answer: (c) Plastic
In simple words: Plastic is an insulator.

Exam Tip: Insulators prevent electric shocks.

Question 3. Switch is 'OFF' when
a) circuit is complete
b) Circuit is not complete
c) Current is flowing in the circuit
d) Cell is fully charged
Answer: (b) Circuit is not complete
In simple words: OFF switch opens the circuit.

Exam Tip: OFF = Open circuit.

VI. Define the following:

Question 1. Electricity
Answer: A form of energy resulting from the existence of charged particles (like electrons) is called electricity.
In simple words: Flow of electric charge providing energy.

Exam Tip: Powers household appliances and lights.

Question 2. Switch
Answer: A simple device used to break or complete an electric circuit is called a switch.
In simple words: Device to turn electrical appliances ON or OFF.

Exam Tip: Controls circuit continuity safely.

Question 3. Electric circuit
Answer: A closed, continuous path through which electric current flows from one terminal of a cell to the other is called an electric circuit.
In simple words: Complete pathway for electric current.

Exam Tip: Must have a source, wires, load, and switch.

VII. Distinguish between: Conductors and Insulators of electricity

Question 1. Conductors and Insulators of electricity
Answer:
Conductors: Materials that allow electric current to pass through them easily (e.g., metals like copper, iron, graphite).
Insulators: Materials that do not allow electric current to pass through them (e.g., rubber, plastic, wood, air).
In simple words: Conductors let electricity pass; insulators block it.

Exam Tip: Insulators protect us from electric shocks.

VIII. Explain the direction of electric current in an electric circuit with the help of a diagram.

Question 1. Explain the direction of electric current in an electric circuit.
Answer: In an electric circuit, electric current flows conventionally from the positive terminal (+) of the electric cell to the negative terminal (-) through the external circuit wires and appliances like a bulb.
In simple words: Current flows from the positive terminal to the negative terminal outside the cell.

Exam Tip: Always draw arrow marks from positive (+) to negative (-) in circuit diagrams.

IX. Draw, colour and label an electric bulb.

Question 1. Draw, colour and label an electric bulb.
Answer: An electric bulb consists of a glass chamber, metal casing, filament (tungsten wire), support wires, and a metal contact (base disc).
In simple words: A bulb has a glass case, filament, and metal terminals.

Exam Tip: Label the filament, terminal, glass case, and metal base clearly.

X. Value based questions:

Question 1. What does this above sign warn people about?
Answer: It warns people about high voltage electrical danger and risk of fatal electric shock near power poles and substations.
In simple words: Warning sign for high voltage electricity danger.

Exam Tip: Skull and crossbones with lightning bolt indicates severe electrical hazard.

Question 2. What values should you develop on knowing about the above warning?
Answer: We should develop cautiousness, alertness, safety awareness, and obedience to safety rules regarding electricity.
In simple words: Developing caution and respect for electrical safety rules.

Exam Tip: Safety first mindset prevents electrical accidents.

Question 3. Which source of electricity is safe for you for your classroom activities?
Answer: Electric cells (dry cells) are safe for classroom activities because they provide low voltage current that does not cause dangerous shocks.
In simple words: Dry cells are safe low-voltage power sources.

Exam Tip: Never use mains household electricity for school experiments.

Question 4. Is it safe to touch electric switches and electric appliances with wet hands? Why?
Answer: No, it is not safe because water is a conductor of electricity. Wet hands can cause electric current to pass through the body, leading to a severe electric shock.
In simple words: No, water conducts electricity and can cause dangerous shocks.

Exam Tip: Always keep hands dry when operating electrical switches.

Question 5. Is air a good conductor of electricity?
Answer: No, dry air is a poor conductor (insulator) of electricity.
In simple words: Air does not conduct electricity under normal conditions.

Exam Tip: Insulating property of air prevents continuous sparking between spaced wires.

CH-15 AIR AROUND US

I. Fill in the blanks:

Question 1. Air is really not one substance but a __________________.
Answer: mixture of gases
In simple words: Air contains nitrogen, oxygen, argon, carbon dioxide, and other gases.

Exam Tip: Air is a mixture, not a single chemical compound.

Question 2. The component of air that supports burning is called ___________.
Answer: oxygen
In simple words: Oxygen is essential for combustion and respiration.

Exam Tip: Without oxygen, fires cannot burn.

Question 3. The aquatic animals use dissolved _______ in water for respiration.
Answer: oxygen
In simple words: Fish breathe oxygen dissolved in water using gills.

Exam Tip: Aquatic life depends on dissolved oxygen.

Question 4. ____________ and __________ present inside the nose prevent dust particles from getting entry into the respiratory system.
Answer: Fine hair, mucus
In simple words: Nose hairs and mucus filter dust out of inhaled air.

Exam Tip: Natural respiratory filtration system.

Question 5. _______and ________ are the gases which comprise 99% of the air.
Answer: Nitrogen, oxygen
In simple words: Nitrogen (~78%) and oxygen (~21%) make up 99% of air.

Exam Tip: Remember atmospheric gas percentages.

Question 6. ________________ is the place in nature for gaseous exchange.
Answer: Atmosphere (or lungs / stomata)
In simple words: Atmosphere acts as the global reservoir for gaseous exchange.

Exam Tip: Balanced via photosynthesis and respiration.

Question 7. Air in motion is called _____________.
Answer: wind
In simple words: Moving air is called wind.

Exam Tip: Caused by uneven heating of the earth.

II. Write true or false:

Question 1. Air is a mixture but not an element.
Answer: True
In simple words: Air is a mixture of various gases.

Exam Tip: Components retain their individual properties.

Question 2. Air is an opaque material.
Answer: False
In simple words: Air is transparent; we can see through it clearly.

Exam Tip: Transparent medium allows light passage.

Question 3. Air contains water vapour.
Answer: True
In simple words: Moisture is always present in the atmosphere as water vapor.

Exam Tip: Humidity levels vary with weather.

Question 4. The major part of air is nitrogen.
Answer: True
In simple words: Nitrogen constitutes about 78% of air.

Exam Tip: Most abundant gas in the atmosphere.

Question 5. Plants produce oxygen through photosynthesis.
Answer: True
In simple words: Plants release oxygen as a byproduct of photosynthesis.

Exam Tip: Vital for maintaining atmospheric oxygen balance.

Question 6. Carbon dioxide is produced during burning.
Answer: True
In simple words: Combustion produces carbon dioxide gas.

Exam Tip: Burning fuels release carbon dioxide into the air.

III. Name the following:

Question 1. The gas which supports burning.
Answer: Oxygen
In simple words: Oxygen is necessary for fires to burn.

Exam Tip: Combustion supporter.

Question 2. Any two properties of air.
Answer: Air occupies space and exerts pressure.
In simple words: Air has weight and takes up space.

Exam Tip: Fundamental physical characteristics of air.

IV. Define: Atmosphere

Question 1. Atmosphere
Answer: The blanket of air that surrounds the Earth is called the atmosphere.
In simple words: The layer of air surrounding our planet.

Exam Tip: Held in place by Earth's gravity.

CHAPTER: 16 GARBAGE IN, GARBAGE OUT

I. Fill in the blanks:

Question 1. Method of making compost using _____________ is called vermicomposting.
Answer: red worms
In simple words: Composting using earthworms/red worms.

Exam Tip: Red worms speed up organic waste decomposition.

Question 2. Converting plant and animals wastes into manure is called ______.
Answer: composting
In simple words: Natural breakdown of organic waste into nutrient-rich manure.

Exam Tip: Eco-friendly waste management method.

Question 3. ____________ is an area where the garbage is collected.
Answer: Landfill
In simple words: Designated low-lying area for dumping city garbage.

Exam Tip: Landfills are covered with soil after filling.

Question 4. We need to generate ____________ waste.
Answer: less (minimal)
In simple words: Reducing waste generation protects the environment.

Exam Tip: Follow the 3Rs: Reduce, Reuse, Recycle.

II. Write true or false:

Question 1. Paper can be recycled to get useful products.
Answer: True
In simple words: Old paper is recycled into new paper products.

Exam Tip: Conserves trees and water.

Question 2. Drains get choked due to plastic thrown by us.
Answer: True
In simple words: Discarded plastic bags block drainage pipes.

Exam Tip: Plastic pollution causes urban waterlogging.

Question 3. Plastics are eco-friendly.
Answer: False
In simple words: Plastics are non-biodegradable and harm the environment.

Exam Tip: Plastics persist in soil for hundreds of years.

Question 4. Red worms eat up on green leaves on trees and make compost.
Answer: False
Answer: False
In simple words: Red worms feed on decaying organic kitchen waste, not living leaves on trees.

Exam Tip: Red worms require moisture and rotting plant/vegetable matter.

Question 5. Plastics give out harmful gases up on heating or burning.
Answer: True
In simple words: Burning plastic releases toxic gases polluting the air.

Exam Tip: Never burn plastic waste.

III. Value based questions:

Question 1. Should you make faces at the rag picker while seeing him do the job? Why?
Answer: No, we should not make faces at rag pickers. They perform an important job by sorting recyclable waste, which helps keep our environment clean.
In simple words: No, we should respect rag pickers for helping recycle waste.

Exam Tip: Respect all labor and recognize recycling contributions.

Question 2. Why is the garbage giving out the foul smell?
Answer: Garbage gives out a foul smell due to the rotting and decomposition of organic waste (like leftover food) by bacteria and fungi.
In simple words: Rotting organic waste produces foul gases.

Exam Tip: Bacterial decomposition of food waste causes unpleasant odors.

Question 3. What do you think, the rag picker would do with those collected poly bags?
Answer: The rag picker would sell the collected poly bags to scrap dealers, who send them to recycling units to make recycled plastic items.
In simple words: Sell them to scrap dealers for recycling.

Exam Tip: Rag picking contributes informally to waste recycling chains.

Question 4. What possible situations can arise if the poly bags are left there in the garbage?
Answer: Leaving poly bags in garbage can choke drains, pollute soil, get swallowed by stray animals causing choking, and prevent rainwater from seeping into the ground.
In simple words: Stray animals might eat them, drains get choked, and soil gets polluted.

Exam Tip: Plastic bags are major environmental hazards.

Question 5. What values should you attribute for the society for minimizing poly bags pollution?
Answer: We should promote eco-friendly habits like using cloth or jute bags, reducing single-use plastics, reusing carry bags, and spreading environmental awareness.
In simple words: Using cloth bags and reducing plastic usage.

Exam Tip: Encourage sustainable habits in community living.