Living Creatures: Exploring their Characteristics — NCERT Solutions, AI Tutor & Practice

Understand: Living organisms differ from non-living things because they carry out certain life processes.

Common characteristics of living organisms:

1. Growth – They increase in size over time.
2. Nutrition – They need food for energy and growth.
3. Respiration – They exchange gases (take in oxygen, release carbon dioxide).
4. Response to stimuli – They react to changes around them (touch, light, heat).
5. Excretion – They remove waste from the body.
6. Reproduction – They produce more of their own kind.
7. Movement – Most show some form of movement.

Conclude: Any object that shows all these features is considered a living organism.

Understand: A car does move and consumes petrol, which may look like nutrition.

Analyze:

• A car cannot grow on its own.
• It cannot reproduce to make new cars by itself.
• It does not respire or excrete biological waste.
• It cannot respond to stimuli independently; a driver operates it.

Conclude: Since a car shows only apparent movement and 'feeding' but lacks the other life characteristics, it is a non-living object.

Understand: Response to stimuli is a sign of life. Plants respond even though they stay rooted.

Examples of plant responses:

1. Sunflower turns its flower head towards the direction of sunlight.
2. Touch-me-not (Mimosa) folds its leaves when touched.
3. Roots grow downward (towards gravity) and shoots grow upward towards light.
4. Some flowers open in the day and close at night.

Conclude: Plants respond to stimuli such as light, touch, and gravity, proving they are living even without moving location.

Understand: Both a living plant and a growing sand heap increase in size, but the process is different.

| Feature | Living organisms | Non-living things | |---------|-----------------|-------------------| | Direction of growth | From inside the body | By adding material from outside | | Control | Follows a definite pattern | No fixed pattern | | Life process | Uses food and energy | No use of food | | Example | A puppy growing into a dog | A sand heap growing bigger |

Conclude: Growth in living things is internal and organised, while in non-living things it is merely external accumulation.

Understand: Nutrition is a basic life process common to all organisms.

Roles of food:

1. Provides energy to carry out life activities.
2. Helps in growth of the body.
3. Helps in repair of damaged or worn-out parts.
4. Keeps the body healthy and able to fight disease.

Note: Plants make their own food by photosynthesis, while animals depend on plants or other animals for food.

Conclude: Every living organism needs food to survive, grow, and stay healthy.

Understand: Both terms are related to gases, but they are not the same.

Breathing: The physical act of taking in air (oxygen) and giving out air (carbon dioxide).

Respiration: The life process in which the food inside the body is broken down using oxygen to release energy.

Difference:

• Breathing is the exchange of gases.
• Respiration is the release of energy from food using that oxygen.

Conclude: Breathing helps supply the oxygen needed for respiration, which is the actual energy-releasing process in all living cells.

Understand: Every individual organism eventually dies, so reproduction is essential.

Analyze:

• Through reproduction, organisms produce new individuals of their own kind.
• This ensures the continuation of their species (kind).
• Plants reproduce through seeds, spores, or other parts; animals reproduce by laying eggs or giving birth.

Conclude: Reproduction keeps a species alive over generations, even though individual members die. Without it, a kind of organism would disappear from the Earth.

Understand: We test each item against the characteristics of living things.

| Item | Living / Non-living | Reason | |------|--------------------|--------| | (a) Mushroom | Living | It grows, needs nutrition, and reproduces (by spores) | | (b) River water | Non-living | It flows but does not grow, feed, or reproduce | | (c) Earthworm | Living | It moves, feeds, respires, and reproduces | | (d) Mobile phone | Non-living | It works only when charged and cannot grow or reproduce |

Conclude: Only the mushroom and earthworm are living because they show all life characteristics.

Understand: During life processes, harmful waste materials are produced in the body.

Excretion: The process of removing waste substances produced inside the body.

Why it is necessary:

1. Waste materials can be harmful or poisonous if they collect inside.
2. Removing them keeps the body healthy and working properly.
3. Examples: humans remove urine and sweat; plants release some waste through leaves.

Conclude: Excretion is essential because it keeps the body free of harmful wastes, allowing life processes to continue normally.

Understand: A dry seed appears inactive, showing no obvious signs of life.

Analyze:

• A dry seed is in a resting (dormant) state; its life processes are very slow and not visible.
• When given water, air, and warmth, the seed germinates and grows into a new plant.
• This ability to grow into a plant shows it contains life.

Conclude: A dry seed is living but in a dormant state. Its life becomes active once suitable conditions are provided.

Understand: Movement is a characteristic of living things, but it looks different in animals and plants.

Movement in animals:

1. A bird flies in the air.
2. A fish swims in water.

Movement in plants (parts move, plant stays fixed):

1. A sunflower turns towards sunlight.
2. Leaves of the touch-me-not plant fold when touched.

Conclude: Animals usually move their whole body from place to place, while plants show movement in their parts while staying rooted.

Understand: The change from caterpillar to butterfly involves several life processes.

Characteristics shown:

1. Growth – The caterpillar grows and changes into a butterfly.
2. Nutrition – The caterpillar eats leaves for energy and growth.
3. Movement – Both the caterpillar and butterfly move.
4. Reproduction – The adult butterfly later lays eggs to produce new individuals.
5. Response to stimuli – It responds to light and touch.

Conclude: The caterpillar-to-butterfly change clearly shows that it is a living organism displaying growth, nutrition, movement, and reproduction.