Grade 4, Science Olympiad (CBSE) - Human Needs

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Grade 4 | Science | Human Needs, Human Needs, Olympiad, CBSE, ICSE, Maths Olympiad, Science Olympiad, English Olympiad

Science – Human Needs (Clothing, Care, Safety & First Aid)

Clothes protect us from heat, cold, rain, dust and insect bites. They also signal identity through uniforms and traditional dresses. Understanding fibres ? fabrics ? clothes, proper care, and basic safety & first aid helps us choose wisely for climate and activity.

Overview

Protection: sunburn, cold winds, rain, dust, scratches, insect bites.
Comfort & hygiene: breathable clothes prevent rashes and absorb sweat.
Identity: uniforms show role/profession; traditional wear shows culture & region.
Sustainability: repair, reuse, donate, and choose durable clothes.

From Fibres to Fabrics

Fibres are thin strands twisted into yarn, then woven/knitted into fabric. Fibres can be natural (plant/animal) or man-made (synthetic or regenerated).

Type	Examples	Core properties	Typical uses
Plant	Cotton, Linen (flax), Jute	Breathable; cotton very absorbent; jute very strong/coarse	Summer wear, towels; sacks & ropes (jute)
Animal	Wool, Silk	Wool traps air (warm); silk is lustrous yet weak when wet	Winter wear (wool); festive garments (silk)
Man-made	Rayon, Nylon, Polyester, Acrylic	Strong, quick-dry, low absorbency (nylon/polyester); acrylic is wool-like	Rainwear, sportswear; warm sweaters (acrylic)

Plant Fibres (Stem/Seed)

Cotton

From seed fluff of cotton plant.
Highly absorbent, breathable, soft.
Best for hot, humid climates; dries slowly.

Linen

From flax stem.
Cool, smooth, quick-dry; wrinkles easily.
Premium summer shirts, dresses.

Jute

From jute stem (bast fibre).
Very strong & coarse.
Sacks, ropes, eco-bags; not for soft clothing.

Animal Fibres

Wool

From sheep/goat (pashmina), alpaca etc.
Crimped fibres trap air ? excellent insulation.
Best for winter; keep dry and clean.

Silk

From silkworm cocoon.
Light, shiny, drapes well; weak when wet.
Wash gently with mild soap; avoid harsh sun.

Man-made Fibres

Fibre	Made from	Key strengths	Typical garments
Rayon (viscose)	Regenerated cellulose	Silk-like drape; decent absorbency	Dresses, linings
Nylon	Synthetic polymer	Very strong, elastic, water-resistant	Raincoats, ropes, sports gear
Polyester	Synthetic polymer (PET)	Wrinkle-resistant, quick-dry, durable	Jerseys, daily wear, blends
Acrylic	Synthetic polymer	Warm, light, wool-like	Sweaters, blankets

Exam tip: For raincoats prefer nylon/polyester (low water absorption, quick-dry). For daily school uniforms, cotton-polyester blends add breathability + easy care.

Choosing Clothes by Climate & Activity

Climate

Hot/Humid: cotton/linen; light colours reflect heat.
Cold: wool or acrylic layers trap warm air.
Rainy: coated nylon/polyester; tight seams.
Desert sun: loose, light-coloured cotton; head cover.

Safety & Activity

Cooking/Labs: cotton (synthetics may melt); avoid loose sleeves near flame.
Sports: stretch & quick-dry synthetics; breathable mesh panels.
Night cycling/jogging: reflective strips improve visibility.

Traditional Dresses & Uniforms

India – Examples

Maharashtra: nauvari saree.
Kerala: mundu with neriyathu.
West Bengal: taant/red-bordered saree.
Kashmir: pheran (warm gown).
Punjab: salwar-kameez; kurta with pajama/dhoti.

Uniforms – Why?

Identify profession/role quickly.
Functional features: pockets, flame-resistant fabric, camouflage.

Common Uniforms

Doctor: white coat; Nurse: scrubs.
Lawyer: black coat & band.
Police: khaki; Soldier: camouflage.
Firefighter: flame-resistant suit; Chef: white coat & hat.

Care & Storage of Clothes

Read care labels; wash delicately for silk/wool; avoid harsh detergents.
Sort by colour and fabric; wash delicates separately.
Dry darks/silk in shade; cotton can sun-dry to remove germs.
Store clean and fully dry; use mothballs or neem leaves for wool/silk.
Mend small tears and reattach buttons early to prevent larger damage.
Be planet friendly: repair, reuse, donate, upcycle.

Safety Rules (Home, Road, Playground, Class/Lab)

Home & Electricity

Keep floors dry; wipe spills immediately.
Use tongs/thick cloth for hot vessels.
Never touch electrical devices with wet hands; avoid loose wires.

Road & Playground

Walk on footpaths; cross at zebra crossings on green pedestrian signal.
Look right–left–right before crossing; never distract the driver.
Wait your turn on swings/slides; no pushing or running across moving equipment.

First Aid Basics

Cuts & Scrapes

Wash under running water; dab antiseptic.
Cover with sterile gauze; change if soaked.

Minor Burns

Cool under running water 10–20 min.
Do not apply ice, ghee, butter or toothpaste.
Cover with sterile, non-fluffy dressing.

Nosebleed & Fainting

Nosebleed: sit, lean forward, pinch nose 10 min.
Fainting: fresh air, loosen tight clothes, raise legs slightly, avoid crowding.

When in doubt: Call a trusted adult or medical help. First aid is the first help until professionals arrive.

MCQ Achievers (5 tougher items)

A fabric for a raincoat should be chosen mainly for its ______.
- A. high water absorption
- B. ability to trap air
- C. low water absorption and quick drying
- D. shine under sunlight
Which pairing is correct?
- A. Linen – animal fibre
- B. Wool – traps air well
- C. Rayon – natural plant fibre
- D. Jute – used for silk sarees
While storing woollens for months, the most important step is to keep them ______.
- A. slightly damp with perfume
- B. unwashed to preserve oils
- C. clean and completely dry, with mothballs/neem
- D. ironed while still wet
A child has a minor burn from hot tea. The first action should be to ______.
- A. apply toothpaste
- B. cool the area under running water
- C. rub with butter
- D. cover tightly with a woollen cloth
Identify the region most closely linked: nauvari saree.
- A. Kerala
- B. West Bengal
- C. Maharashtra
- D. Kashmir

Show Answers

1-C (rainwear must repel water and dry fast), 2-B (wool insulates by trapping air), 3-C (clean, dry + pest deterrent), 4-B (cooling under running water), 5-C (nauvari is Maharashtrian).

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