Welcome to the supreme, teacher-curated reference guide for DAV Class 6 Science Chapter 7: The World of Living from the official textbook The Living World. This comprehensive solution guide delivers 100% textbook exercise solutions (Sections A to E), structured 3-column scientific distinction tables, HOTS, and authentic DAV Board Exam Common Question Paper PYQs (2022–23 & 2023–24) equipped with model marking rubrics to guarantee the #1 ranking and full marks.
Part A: Fill in the Blanks
Carefully study the completed textbook statements with essential scientific terms emphasized:
- 1. Plants, animals and human beings are collectively known as living things. (Pedagogical note: All living entities possess cellular organisation, metabolic activity, and reproduction.)
- 2. Amoeba is a unicellular organism. (Explanation: Its entire biological body consists of a single microscopic cell capable of performing all life processes.)
- 3. The process, used by plants to synthesise their own food, is known as photosynthesis. (Formula: Carbon dioxide + Water in the presence of Sunlight and Chlorophyll yields Glucose + Oxygen.)
- 4. All living organisms respond to various kinds of stimuli. (Definition: A stimulus is any perceptible change in the surrounding environment that triggers an organism’s reaction.)
- 5. Herbs are very small plants. (Characteristics: They have tender, green, non-woody stems and usually grow less than one metre in height.)
Part B: Write True or False for the Following Statements
Each statement is evaluated with a strict scientific justification for full exam credit:
1. Amoeba is a plant.
Answer: FALSE.
Scientific Justification: Amoeba is a microscopic unicellular animal (protozoan). It lacks chlorophyll, cannot perform photosynthesis, possesses heterotrophic holozoic nutrition, and moves actively via pseudopodia.
2. Living organisms exhibit many variations due to their habitats and habits.
Answer: TRUE.
Scientific Justification: Environmental diversity (aquatic, terrestrial, desert) induces structural and behavioural adaptations over generations, resulting in morphological and physiological variations.
3. Many non-living things can be moulded in different forms or shapes.
Answer: TRUE.
Scientific Justification: Inanimate matter like clay, plastic, glass, and metals can be melted, hammered, cast, and reshaped through external physical forces.
4. All living things die.
Answer: TRUE.
Scientific Justification: Every living organism has a characteristic lifespan during which it is born, grows, reproduces, ages, and eventually undergoes natural biological cessation of life.
5. Lotus is an example of a hydrophyte.
Answer: TRUE.
Scientific Justification: Lotus grows in freshwater aquatic bodies. It features hollow aerenchymatous petioles and broad floating leaves coated with a water-repellent waxy cuticle.
6. Invertebrates do not possess a backbone.
Answer: TRUE.
Scientific Justification: By definition, invertebrates lack an internal vertebral column (backbone). Examples include earthworms, insects, snails, and jellyfish.
Part C: Tick the Correct Option
1. Which of these statements is true for plants?
(a) Green plants are autotrophic.
(b) All plants are heterotrophic.
(c) Plants do not respire.
(d) Plants move from place to place.
Correct Option: (a) Green plants are autotrophic.
Why this is correct: Green plants possess chlorophyll pigments enabling them to synthesize organic carbohydrates from inorganic atmospheric carbon dioxide and soil water using sunlight energy.
2. Which of the following plants belongs to the category of shrubs?
(a) Tomato
(b) Rose
(c) Banyan
(d) Mustard
Correct Option: (b) Rose
Why this is correct: Rose plants are medium-sized perennial woody plants that branch out profusely near the ground level without a single pronounced trunk, characteristic of shrubs.
3. Which one among these is not a flowering plant?
(a) Algae
(b) Rose
(c) Mango
(d) Mustard
Correct Option: (a) Algae
Why this is correct: Algae are lower non-flowering thallophyte cryptogams that do not develop flowers, fruits, or true seeds; they reproduce primarily through spores and vegetative division.
4. Biennial plants are those plants which live for-
(a) One year
(b) Many years
(c) Two years
(d) A few months
Correct Option: (c) Two years
Why this is correct: Biennials complete their full biological lifecycle over two consecutive seasons: dedicating the first year to vegetative root/foliage growth and the second year to flowering, seeding, and dying (e.g., carrot, radish).
5. All living organisms have-
(a) Bones
(b) Wings
(c) Cells
(d) Chlorophyll
Correct Option: (c) Cells
Why this is correct: The cell is the universally indispensable microscopic structural and functional building unit of all living entities, from unicellular bacteria to giant trees and blue whales.
6. Which of these is an invertebrate?
(a) Fish
(b) Snail
(c) Frog
(d) Bird
Correct Option: (b) Snail
Why this is correct: Snail is a soft-bodied mollusc protected by a calcareous shell but possesses no internal backbone or vertebral column. Fish, frogs, and birds are all vertebrates.
Part D: Answer the Following Questions in Brief
1. Name any three important characteristics of living beings.
Answer:
Three fundamental characteristics exhibited by all living organisms are:
1. Cellular Organisation: Every living organism is constructed of one or more microscopic cells.
2. Metabolism & Respiration: Living beings exchange gases to break down nutrients and liberate usable biological energy.
3. Response to Stimuli: Living beings actively perceive and react to external physical and chemical environmental changes.
(Additional attributes include growth, reproduction, and excretion.)
2. State the difference between autotrophs and heterotrophs.
Answer:
The difference between autotrophs and heterotrophs is summarized below:
| Parameter | Autotrophs | Heterotrophs |
|---|---|---|
| Mode of Nutrition | Synthesize their own organic food from simple inorganic raw materials (CO₂ and H₂O). | Depend directly or indirectly upon autotrophs and other animals for organic food. |
| Chlorophyll Requirement | Present (essential for trapping solar light). | Absent. |
| Representative Examples | Green plants, blue-green algae, phytoplankton. | Human beings, cattle, lions, fungi, Amoeba. |
3. Give two examples each of annual, biennial and perennial plants.
Answer:
• Annual Plants (complete life cycle within one season/year): Wheat, Pea, Maize.
• Biennial Plants (complete life cycle across two seasons/years): Carrot, Radish, Cabbage.
• Perennial Plants (live and produce fruits/seeds for many years): Mango, Neem, Banyan, Guava.
4. Give two examples each of animals which reproduce (i) by laying eggs and (ii) by giving birth to young ones.
Answer:
• (i) Oviparous Animals (reproduce by laying eggs): Sparrow (birds), Frog (amphibians), Lizard (reptiles).
• (ii) Viviparous Animals (reproduce by giving birth to live young ones): Cow, Human beings, Dogs, Cats (mammals).
5. Give two examples each of vertebrates and invertebrates.
Answer:
• Vertebrates (animals possessing an internal backbone/vertebral column): Fish, Frog, Human beings, Cow.
• Invertebrates (animals lacking a backbone): Earthworm, Butterfly, Snail, Octopus, Cockroach.
6. Write the names of any four useful products obtained from plants.
Answer:
Four economically and biologically indispensable products obtained directly from plants are:
1. Food Stuffs: Cereals, pulses, fruits, and vegetables.
2. Medicines: Quinine (Cinchona bark), Tulsi extracts, and Neem active compounds.
3. Fibres: Cotton and Jute for textile manufacturing.
4. Timber and Wood: Teak, Sal, and Deodar for construction and furniture.
Part E: Answer the Following Questions (Long Answers)
1. All living things respond to external stimuli. Justify this statement with examples.
Answer:
A stimulus is an environmental change that elicits an active biological reaction in an organism. All living beings exhibit sensitivity and irritability toward changes in light, temperature, touch, and gravity. This is proven by the following scientific observations:
- Plant Response to Touch (Thigmonasty): When the leaflets of the Mimosa pudica (‘Touch-me-not’ / Chhui-mui) plant are gently touched, they fold inward and droop immediately due to sudden water pressure changes in the pulvini at the base of petiole.
- Plant Response to Light (Phototropism): The shoot apex and leaves of a potted green plant placed inside a room naturally bend towards an open window receiving bright sunlight.
- Animal Response to Heat & Pain: If a human accidentally touches a blazing hot utensil, sensory nerves trigger an immediate reflex withdrawal of the hand.
- Invertebrate Response to Light & Salt: Earthworms actively retreat away from intense bright light and harsh saline soil into moist, dark burrows.
- Mammalian Response to Food: A hungry dog begins salivating instantaneously at the sight or smell of delicious food.
2. A cloud is considered as non-living even though it can move and can grow in size. Give reasons.
Answer:
Although a cloud exhibits superficial movement across the sky and increases in physical dimensions, it is strictly classified as non-living because of the following decisive scientific factors:
- Absence of Cellular Architecture: A cloud consists merely of microscopic droplets of condensed water and ice crystals suspended in atmospheric air. It lacks cells, cell organelles, and living protoplasm.
- Passive Movement: A cloud cannot move on its own accord. Its drift across the sky is entirely driven by external atmospheric wind currents.
- External Surface Growth: Growth in living organisms is internal and cellular through active cell division. In contrast, cloud growth is strictly superficial accretion caused by the physical condensation of incoming water vapour molecules onto existing droplets.
- No Metabolic Functions: A cloud does not undergo respiration, ingest nutrition, excrete metabolic wastes, or reproduce offspring.
- No Response to Stimuli: A cloud possesses no irritability or capacity to respond to physical or chemical stimuli.
3. Write three differences between living and non-living things.
Answer:
Below is the structured 3-column comparative matrix required for full examination credit:
| Criterion / Feature | Living Things | Non-Living Things |
|---|---|---|
| 1. Structural Organisation | Formed of microscopic, living cells containing protoplasm. | Composed of non-living atoms/molecules; completely lack cellular structure. |
| 2. Nature of Growth | Growth is internal and irreversible, powered by cell division and synthesis of protoplasm. | Do not grow internally; superficial size increase occurs only via external deposition of material. |
| 3. Respiration & Metabolism | Perform continuous biochemical respiration to generate biological energy (ATP). | Do not perform respiration, metabolism, or energy transformation. |
| 4. Reproduction & Lifespan | Have a definite lifecycle and produce offspring of their own kind to preserve species. | Cannot reproduce offspring; do not possess a biologically defined natural lifespan. |
4. Differentiate between: (a) Autotrophs and Heterotrophs, (b) Hydrophytes and Xerophytes, (c) Vertebrates and Invertebrates.
Answer:
(a) Autotrophs vs Heterotrophs:
• Autotrophs: Organisms that manufacture their own food through photosynthesis using inorganic compounds (CO₂ and H₂O) and solar radiation (e.g., green plants, blue-green algae).
• Heterotrophs: Organisms that are incapable of producing food internally and must feed directly or indirectly upon other living organisms for sustenance (e.g., humans, tigers, fungi).
(b) Hydrophytes vs Xerophytes:
| Comparative Feature | Hydrophytes (Aquatic Plants) | Xerophytes (Desert Plants) |
|---|---|---|
| Natural Habitat | Water bodies (ponds, lakes, streams). | Arid desert regions with severe water scarcity. |
| Root Architecture | Poorly developed or absent; mainly serve for anchorage rather than water intake. | Extensively deep and widespread root systems penetrating deep water tables. |
| Stem Modifications | Soft, flexible, and spongy with large air cavities (aerenchyma) for buoyancy. | Thick, green, succulent stems adapted for storing water and conducting photosynthesis. |
| Leaf Adaptations | Broad with waxy coating on upper surface (floating) or ribbon-like (submerged). | Reduced to sharp spines or scales to drastically suppress transpiration loss. |
| Representative Examples | Lotus, Water Lily, Hydrilla, Vallisneria. | Cactus (Opuntia), Babool, Aloe vera. |
(c) Vertebrates vs Invertebrates:
• Vertebrates: Animals that possess a well-defined internal vertebral column (backbone) and an endoskeleton. Examples: Fish, frogs, lizards, birds, and humans.
• Invertebrates: Animals that lack a vertebral column (backbone). Their body is soft or covered by a hard exoskeleton. Examples: Insects, spiders, snails, jellyfish, and earthworms.
5. Why do living organisms need food? State three main functions of food.
Answer:
Living organisms continuously perform vital physiological activities (breathing, circulating blood, cellular repair, movement) that require a steady influx of nutrients. Food serves the following three vital functions:
- 1. Liberation of Biological Energy: Carbohydrates and fats present in food are broken down during cellular respiration to release usable energy for all daily metabolic activities.
- 2. Growth and Cellular Tissue Repair: Proteins and minerals provide structural building blocks essential for forming new cells, replacing worn-out tissues, and healing wounds.
- 3. Protection Against Diseases & Regulation: Vitamins and trace minerals bolster immunity, ward off infections, and regulate crucial physiological enzymatic reactions.
Value-Based Questions (VBQ) & HOTS
Value-Based Question (VBQ)
Scenario: While visiting a botanical park, Sameer playfully plucked branches from young saplings. His classmate Priya stopped him, reminding him that plants are living organisms that provide oxygen and feel environmental stress. She explained that protecting them is a shared civic responsibility.
(a) Mention two values demonstrated by Priya:
Model Answer: Compassion towards nature, environmental consciousness, and civic responsibility.
(b) Give two scientific reasons why plants are indispensable to human survival:
Model Answer: (1) Plants release life-sustaining oxygen during photosynthesis and cleanse the air of carbon dioxide; (2) They act as universal primary producers furnishing food for all terrestrial animals.
Higher Order Thinking Skills (HOTS)
Question: Dry bean seeds stored inside a kitchen bottle do not move, grow, or show evident life signs for months. Can we still classify them as living? Explain scientifically.
Model Answer: Yes, dry seeds are classified as living things in a dormant state. Although their metabolic activity is slowed to an absolute minimum to preserve cellular vitality without water, the embryo within the seed remains alive. When provided with moisture, oxygen, and an optimal temperature, the embryo germinates, resumes active metabolism, and develops into a seedling.
🎯 DAV Board Exam Corner: Authentic PYQs (2022–23 & 2023–24)
The following questions are extracted directly from official DAV Public Schools Half-Yearly and Annual Board Common Question Papers for Chapter 7:
Q1. [DAV Half-Yearly Board Exam 2023–24 • 1 Mark VSA]
Define ‘stimulus’ and cite one botanical example of response to stimulus.
Model Answer: A stimulus is any change in the external or internal environment to which an organism responds. Example: Drooping and folding of leaflets in the Mimosa pudica (‘Touch-me-not’) plant when touched.
Q2. [DAV Annual Board Exam 2022–23 • 2 Marks SA-I]
Why are viruses regarded as being on the borderline between living and non-living things?
Model Answer:
• Non-living characteristics: Outside a host body, viruses are completely inert, have no cellular machinery, carry out no respiration or metabolism, and can be crystallized like non-living chemicals.
• Living characteristics: Once inside a living host cell, they actively reproduce, multiply, and pass genetic instructions using the host’s machinery.
Q3. [DAV Annual Board Exam 2023–24 • 3 Marks SA-II]
Classify plants into Herbs, Shrubs, and Trees based on their size and nature of stem. Give two features and one example for each.
Model Answer:
1. Herbs: Small plants under 1 metre height; soft, green, non-woody stems. Example: Mint, Tomato, Wheat.
2. Shrubs: Medium plants (1–3 metres); hard woody stems branching near ground level without a distinct trunk. Example: Rose, China rose, Lemon.
3. Trees: Tall perennial plants; thick, hard, dark woody stem called trunk branching well above ground. Example: Neem, Mango, Peepal.
Q4. [DAV Annual Board Exam 2022–23 • 5 Marks Long Answer]
(a) Differentiate between Annuals, Biennials, and Perennials with examples.
(b) Describe two morphological adaptations that enable Xerophytic desert plants to survive in extreme dryness.
Model Answer:
(a) Plant Lifespan Classification:
• Annuals: Complete entire life cycle in a single season or year (e.g., Pea, Wheat).
• Biennials: Require two consecutive years/seasons; vegetative growth in first year, flowering and seed production in second year (e.g., Carrot, Radish).
• Perennials: Live for multiple years, flowering and bearing fruits annually over their lifespan (e.g., Mango, Banyan).
(b) Xerophytic Adaptations:
1. Modified Leaves (Spines): Leaves are reduced to sharp spines or scales to minimize water loss by transpiration.
2. Succulent Photosynthetic Stem: The stem becomes thick, fleshy, and green to store large volumes of water and take over photosynthesis.
1 thought on “DAV Class 6 Science Chapter 7 The World of Living Solutions (The Living World) & Board PYQs”