🧬 Biology · Topic 1 of 10
Start with the study notes on Living World: Characteristics, Habitat & Adaptation (definitions, examples and a quick revision), then work through 60 practice questions, each with the correct answer and a clear explanation of why it is right. When you are ready, take this topic as an interactive quiz to test yourself.
Topic overview
All living things share these features:
Examples:
A stimulus is any change in the surroundings, such as light, heat, touch or sound, that produces a reaction.
Examples:
Remember: Plants cannot walk about, but they do move parts of their bodies and respond to stimuli.
A habitat is the place where an organism naturally lives. It provides food, water, air, shelter and a place to breed.
An adaptation is a special feature of body or behaviour that helps an organism survive in its habitat. Adaptations develop slowly, over many generations.
Remember: Destroying a habitat leaves its organisms nowhere to live. Most cannot simply move elsewhere, so protecting habitats protects species.
| Misconception | Correct understanding |
|---|---|
| Anything that moves is alive. | Cars and clouds move but don't grow, respire or reproduce. |
| Plants are not alive because they don't move. | Plants grow, respire, reproduce and respond to stimuli. |
| An animal can grow an adaptation when it needs one. | Adaptations develop slowly over many generations. |
| Dolphins and whales breathe with gills. | They are mammals and breathe air with lungs. |
| Hibernation and aestivation are the same. | Hibernation is a winter sleep; aestivation is a summer sleep. |
Name four characteristics of all living things.
They need food, respire, grow and reproduce (and also excrete and respond to stimuli).
Is sunlight a biotic or an abiotic component?
Abiotic: it is non-living.
Why are a cactus's leaves reduced to spines?
To reduce water loss in the dry desert.
How does a camel save water?
It passes very little urine and hardly sweats.
Why do fish have a streamlined body?
It reduces water resistance, so they swim easily.
How do dolphins breathe?
With lungs, taking in air through a blowhole on top of the head.
What is camouflage? Give an example.
Blending with the surroundings to hide, e.g. a chameleon changing colour.
What is the difference between hibernation and aestivation?
Hibernation is a winter sleep; aestivation is a summer sleep.
Key takeaway: Living things share the signs of life, live in habitats that meet their needs, and survive there thanks to adaptations built up over many generations.
Notes written by Velnov for Class 6–8 students, following the topics of the NCERT science syllabus.
Q1. easy
Which of the following is a characteristic of ALL living things?
Answer: A — They grow, respire, reproduce and respond to stimuli
All living organisms need food, respire, grow, excrete, reproduce, respond to stimuli and eventually die. Not all can move about or fly - plants, for instance, stay rooted.
Q2. easy
The response of living things to a change in their surroundings is called a response to:
Answer: A — A stimulus
A stimulus is any change - light, heat, touch, sound or smell - that produces a reaction. Pulling your hand back from a hot object is a response to a stimulus.
Q3. medium
The touch-me-not plant (Mimosa) folds its leaves when touched. This shows that plants:
Answer: A — Respond to stimuli
Though plants cannot move from place to place, they clearly respond to stimuli - leaves fold on touch, shoots bend towards light and roots grow towards water.
Q4. medium
The process by which living organisms release energy from food is called:
Answer: A — Respiration
During respiration, oxygen is used to break down food, releasing energy along with carbon dioxide and water. All living things respire, day and night.
Q5. medium
The removal of waste products from the body is called:
Answer: A — Excretion
Excretion removes harmful waste produced during life processes. Animals excrete urine and sweat; plants store or release wastes through leaves, bark and gums.
Q7. medium
The place where an organism lives naturally is called its:
Answer: A — Habitat
A habitat provides food, water, air, shelter and a place to reproduce. Forests, deserts, ponds, oceans and mountains are all different habitats.
Q8. medium
The special features that help an organism survive in its habitat are called:
Answer: A — Adaptations
Adaptations develop over long periods and may be in body structure, function or behaviour. A camel's hump and a fish's gills are both adaptations.
Q10. medium
Which of these is an ABIOTIC component of a habitat?
Answer: A — Sunlight
Sunlight, air, water, soil, rocks and temperature are non-living (abiotic). Bacteria, grass and earthworms are living, so they are biotic.
Q12. medium
A camel is adapted to desert life because it:
Answer: A — Has long legs, excretes little urine, hardly sweats and stores fat in its hump
Long legs keep the body away from the hot sand, and passing very little urine and almost no sweat conserves water. The hump stores fat that can be used for energy.
Q14. medium
The stem of a cactus is thick, green and fleshy because it:
Answer: A — Stores water and carries out photosynthesis
With no leaves to photosynthesise, the cactus stem takes over that job, and its fleshy tissue stores water to survive long dry periods.
Q16. medium
Animals living in very cold mountain regions usually have:
Answer: A — Thick fur or a layer of fat to keep the body warm
Thick fur, hair and fat under the skin are insulators that trap heat. Yaks, snow leopards and mountain goats all show these adaptations.
Q18. medium
Fish are adapted to live in water because they have:
Answer: A — A streamlined body, gills for breathing and fins for swimming
The streamlined shape reduces resistance while swimming, gills absorb dissolved oxygen from the water, and fins and a tail provide movement and direction.
Q20. medium
Gills help aquatic animals to:
Answer: A — Take in oxygen dissolved in water
Gills are richly supplied with blood vessels. As water flows over them, dissolved oxygen passes into the blood and carbon dioxide passes out.
Q22. medium
Aquatic plants such as water lily have:
Answer: A — Hollow, light stems and broad floating leaves
Air spaces in the stems help the plant float, and broad flat leaves spread on the surface to catch maximum sunlight while staying above the water.
Q24. medium
A frog can live both on land and in water. Such animals are called:
Answer: A — Amphibians
Amphibians like frogs, toads and salamanders have webbed feet and moist skin for water, and lungs and strong hind legs for land.
Q26. medium
Birds are adapted for flying because they have:
Answer: A — Hollow light bones, strong flight muscles and a streamlined body
Hollow bones reduce weight, powerful breast muscles flap the wings, and the streamlined shape and feathers reduce air resistance.
Q28. medium
The ability of an animal to blend with its surroundings to hide from enemies is called:
Answer: A — Camouflage
Camouflage helps prey hide from predators and predators approach prey unnoticed. A chameleon changing colour and a stick insect resembling a twig are examples.
Q30. medium
The long-distance seasonal movement of animals to a more favourable place is called:
Answer: A — Migration
Birds such as the Siberian crane fly thousands of kilometres to warmer regions in winter, returning when conditions improve. This is migration.
Q32. medium
The summer sleep of animals to escape extreme heat is called:
Answer: A — Aestivation
In aestivation, animals such as some snails, frogs and lungfish become inactive in a cool burrow to avoid heat and dryness.
Q34. medium
A lion's eyes are placed at the FRONT of its head, which helps it:
Answer: A — Judge distance accurately while hunting prey
Forward-facing eyes give overlapping fields of view and good depth perception, essential for judging the distance to prey before pouncing.
Q36. medium
Which of these is a characteristic that distinguishes living from non-living things?
Answer: A — Living things grow and reproduce; non-living things do not
Growth from within, reproduction, respiration, excretion and response to stimuli are unique to living things. A car moves and uses fuel, but it cannot grow or reproduce.
Q38. medium
Which of these is NOT a life process?
Answer: A — Rusting
Rusting is a chemical change in a non-living metal. Respiration, excretion, nutrition, growth and reproduction are all life processes.
Q40. medium
Which habitat receives very little rainfall and has extreme temperatures?
Answer: A — Desert
Deserts get very little rain, are extremely hot by day and can be cold at night. Plants and animals there are adapted mainly to conserve water.
Q42. medium
Which of these describes the habitat of a polar bear?
Answer: A — Very cold polar region with snow and ice
Polar bears live in the Arctic. White fur camouflages them against snow, and thick fur plus a layer of fat keeps them warm in freezing temperatures.
Q44. medium
Living organisms need food mainly to:
Answer: A — Get energy, grow and repair damaged parts
Food provides the energy for all life processes, the raw materials for growth, and the substances needed to repair worn-out or injured tissues.
Q46. medium
The bending of a plant shoot towards light is an example of:
Answer: A — Response to a stimulus (light)
This growth response to light is called phototropism. It ensures the leaves receive maximum sunlight for photosynthesis.
Q48. medium
Which of these is a MAN-MADE habitat?
Answer: A — An aquarium
An aquarium, a zoo, a park or a garden is created and maintained by people. Forests, deserts and oceans are natural habitats.
Q50. medium
A group of organisms of the same kind that can reproduce among themselves is called a:
Answer: A — Species
Members of a species share similar features and can breed to produce fertile offspring. Lions form one species, tigers another.
Q52. medium
Birds and mammals are warm-blooded, which means they:
Answer: A — Keep their body temperature nearly constant regardless of the surroundings
Warm-blooded animals maintain a steady internal temperature using energy from food, which lets them stay active in both hot and cold conditions.
Q54. medium
Why do plants in a rainforest often have very LARGE leaves?
Answer: A — To capture as much sunlight as possible under the dense canopy
In a thick forest, little light reaches the lower levels. Large leaf surfaces capture whatever light filters through, and drip tips let heavy rain run off quickly.
Q56. medium
Which of these best explains why organisms in the same habitat often share similar features?
Answer: A — They face the same conditions, so similar adaptations help them survive
Common challenges - heat, cold, lack of water, water currents - favour the same kinds of solutions, so unrelated species in a habitat often look and behave alike.
Q58. medium
Which overall statement about the living world is CORRECT?
Answer: A — Living things show growth, respiration, nutrition, excretion, reproduction and response to stimuli, and each is adapted to its habitat
This sums up the topic: the characteristics of life distinguish living from non-living things, habitats supply what organisms need, and adaptations are the features that let each organism survive where it lives.
Q59. medium
A duck can swim well because it has:
Answer: A — Webbed feet and oily, water-repellent feathers
The skin between a duck's toes acts as a paddle, and oil from a gland near the tail keeps its feathers dry, so the bird stays light and buoyant in water.
Q6. hard
The process by which living beings produce more of their own kind is called:
Answer: A — Reproduction
Reproduction ensures the continuation of a species. Animals reproduce by laying eggs or giving birth; plants reproduce through seeds, spores or vegetative parts.
Q9. hard
The living components of a habitat, such as plants, animals and micro-organisms, are called:
Answer: A — Biotic components
Biotic components are all the living things in a habitat. Non-living things such as air, water, soil, light and temperature are the abiotic components.
Q11. hard
Habitats on land, such as forests, deserts and grasslands, are called:
Answer: A — Terrestrial habitats
Terrestrial means on land. Aquatic habitats are in water - ponds, rivers, lakes, seas and oceans.
Q13. hard
Desert plants like cactus have leaves reduced to SPINES in order to:
Answer: A — Reduce water loss by transpiration
Broad leaves would lose too much water in the dry desert air. Spines lose almost none, and the flattened green stem carries out photosynthesis instead.
Q15. hard
Desert plants have very LONG roots because:
Answer: A — Water is available deep below the surface
The surface soil in a desert is dry, so roots grow very deep or spread wide to reach whatever moisture is available.
Q17. hard
Trees in mountain regions are usually CONE-SHAPED with sloping branches because:
Answer: A — Snow slides off easily and does not break the branches
The conical shape with downward-sloping branches lets snow slide off. The needle-like leaves also shed snow easily and lose little water.
Q19. hard
A STREAMLINED body helps aquatic animals by:
Answer: A — Reducing the resistance of water so they can swim easily
A body that is narrow at both ends and broad in the middle slips through water with minimum drag, so less energy is needed for swimming.
Q21. hard
Dolphins and whales live in water but breathe through:
Answer: A — Lungs, taking air through blowholes at the top of the head
Dolphins and whales are mammals. They must come to the surface to breathe air through blowholes, and can hold their breath for long periods underwater.
Q23. hard
Submerged aquatic plants have narrow, ribbon-like leaves because:
Answer: A — This shape lets water currents flow past without tearing them
Thin, flexible, ribbon-shaped leaves bend with the current rather than resisting it, so they are not damaged by flowing water.
Q25. hard
A frog's webbed feet help it to:
Answer: A — Swim in water
The skin between the toes acts like a paddle, pushing more water with each kick and making the frog an efficient swimmer.
Q27. hard
Birds have hollow bones mainly to:
Answer: A — Reduce body weight, making flight easier
Hollow, air-filled bones are strong but very light. Less weight means less energy is needed to stay airborne.
Q29. hard
Which animal is famous for changing its body colour to match its surroundings?
Answer: A — Chameleon
A chameleon changes colour to blend with leaves and branches, hiding from predators and helping it approach insects unseen.
Q31. hard
The winter sleep of animals like frogs and bears is called:
Answer: A — Hibernation
During hibernation, body activity slows down greatly so the animal survives the cold months on stored fat, with little or no food available.
Q33. hard
A yak has long, thick hair on its body because:
Answer: A — It keeps the animal warm in the very cold mountains
Thick hair traps a layer of air that insulates the yak against the freezing temperatures of the high Himalaya.
Q35. hard
A deer has eyes on the SIDES of its head because this helps it:
Answer: A — See in almost all directions and spot predators
Side-set eyes give a wide field of view, so the deer can watch for danger while grazing. Long ears that turn towards sound and strong legs for running complete its defence.
Q37. hard
Growth in living things is different from the 'growth' of a crystal because living things:
Answer: A — Grow from within by making new cells, while crystals only add material on the outside
Living organisms grow by cell division and internal development. A crystal or a mound of sand simply accumulates material on its surface.
Q39. hard
Grasslands are habitats where the main vegetation is grass, and animals there are adapted with:
Answer: A — Strong legs for running and eyes that spot danger from far
In open grasslands there is little cover, so speed and keen eyesight matter. Deer, zebras and antelopes rely on running to escape predators.
Q41. hard
Earthworms are adapted to live in soil because they:
Answer: A — Have a slippery, moist body that helps them move through the soil and breathe through their skin
The smooth, slimy body slides easily through soil, and gas exchange takes place directly through the moist skin. Earthworms also enrich the soil as they burrow.
Q43. hard
The white fur of a polar bear serves TWO purposes:
Answer: A — It keeps the animal warm and camouflages it against the snow
The dense fur traps heat, and its white colour blends with the ice and snow so the bear can approach seals without being noticed.
Q45. hard
Which statement about movement in living things is CORRECT?
Answer: A — All living things show some movement, but not all can move from place to place
Animals show locomotion, while plants show movement of parts - roots grow downwards, shoots bend towards light, and flowers open and close.
Q47. hard
The growth of roots downwards, towards gravity and water, is an example of a response to:
Answer: A — Gravity and water (stimuli)
Roots grow towards gravity (geotropism) and towards moisture (hydrotropism), anchoring the plant and reaching the water it needs.
Q49. hard
Why is it important to protect natural habitats?
Answer: A — Destroying habitats leaves organisms with nowhere to live, and many species die out
Each organism is adapted to a particular habitat and cannot simply move elsewhere. Cutting forests and filling wetlands drives species towards extinction.
Q51. hard
Animals like snakes and lizards are cold-blooded, which means their body temperature:
Answer: A — Changes with the temperature of the surroundings
Cold-blooded animals cannot regulate their own body heat, so they bask in the sun to warm up and seek shade or burrows to cool down.
Q53. hard
Which adaptation helps a snake move without legs?
Answer: A — A long flexible body with strong muscles and belly scales that grip the ground
A snake pushes its body into S-shaped curves. The broad belly scales catch against the surface, and waves of muscle contraction drive the body forward.
Q55. hard
Mangrove trees growing in salty coastal swamps have special roots that:
Answer: A — Grow upwards out of the mud to take in oxygen
Waterlogged mud contains almost no oxygen, so mangroves grow breathing roots (pneumatophores) that stick up into the air. Stilt roots also anchor them against tides.
Q57. hard
Adaptations develop:
Answer: A — Gradually over many generations, not in a single lifetime
Individuals with helpful features survive and reproduce more successfully, so those features become common over many generations. No animal can develop an adaptation on demand.
Q60. hard
Which feature helps an owl hunt at night?
Answer: A — Large forward-facing eyes, sharp hearing and soft feathers for silent flight
Big eyes gather what little light there is, asymmetrically placed ears pinpoint the smallest rustle, and fringed feathers muffle the sound of the owl's wings so prey never hears it coming.
Practice “Living World: Characteristics, Habitat & Adaptation” as a quiz