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Living and Non-living Things - Characteristics of living things

Grade 3ICSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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Living things need food and water to stay alive and grow. Green plants make their own food using CO2CO_2, water (H2OH_2O), and sunlight.

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Living things breathe to get energy from food. Most animals breathe in Oxygen (O2O_2) and breathe out Carbon Dioxide (CO2CO_2).

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Living things show movement. Animals move from place to place (locomotion), while plants show parts-movement, like a sunflower turning towards the Sun.

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Living things grow and change. A tiny seed grows into a large tree, and a kitten grows into a cat.

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Living things respond to stimuli. For example, the leaves of the 'Touch-me-not' (Mimosa pudicaMimosa\ pudica) plant fold when touched.

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Living things reproduce their own kind. Animals either lay eggs or give birth to young ones; plants produce seeds or spores.

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Living things excrete waste products from their bodies to stay healthy.

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Non-living things do not breathe, eat, grow, move on their own, or reproduce.

📐Formulae

Photosynthesis: 6CO2+6H2O→SunlightC6H12O6+6O2\text{Photosynthesis: } 6CO_2 + 6H_2O \xrightarrow{\text{Sunlight}} C_6H_{12}O_6 + 6O_2

Breathing (Animals): Inhale O2→Exhale CO2\text{Breathing (Animals): } \text{Inhale } O_2 \rightarrow \text{Exhale } CO_2

Breathing (Plants via Stomata): Exchange of O2 and CO2\text{Breathing (Plants via Stomata): } \text{Exchange of } O_2 \text{ and } CO_2

💡Examples

Problem 1:

Why is a car considered a non-living thing even though it can move from one place to another?

Solution:

A car is a non-living thing because its movement is not 'self-directed'.

Explanation:

While a car moves, it requires a driver and fuel (external energy). It does not grow, it does not breathe O2O_2, it does not reproduce, and it does not respond to touch like a living organism.

Problem 2:

Identify the process: A bean seed is planted in soil, and after a few days, a small sprout appears above the ground.

Solution:

This process is called Growth.

Explanation:

Growth is a permanent increase in size and complexity. The seed uses stored energy to develop into a seedling, which is a key characteristic of living things.

Problem 3:

A fish uses its gills to take in O2O_2 dissolved in water. Which characteristic of living things does this represent?

Solution:

This represents Respiration (Breathing).

Explanation:

All living things need to breathe to produce energy. Different animals have different organs for this: humans use lungs, while fish use gills to extract O2O_2 from H2OH_2O.