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Living and Non-living Things - Natural and Man-made things

Grade 3ICSE

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

🔑Concepts

Living things are organisms that display characteristics such as growth, movement, breathing, and reproduction. Examples include plants, animals, and humans.

Non-living things do not grow, breathe, eat, or reproduce. They are further classified into Natural and Man-made things.

Natural things are found in nature and are not created by humans. These can be living (like a tree) or non-living (like the Sun, H2OH_2O in rivers, or rocks).

Man-made things are created by humans using natural materials. Examples include wooden chairs, plastic bottles, and cars.

Living things require O2O_2 (Oxygen) for breathing and release CO2CO_2 (Carbon Dioxide) as a byproduct of respiration.

Green plants are living things that produce their own food using H2OH_2O, CO2CO_2, and sunlight through a process called photosynthesis.

📐Formulae

Living Organism+O2CO2+Energy\text{Living Organism} + O_2 \rightarrow CO_2 + \text{Energy}

CO2+H2OSunlightFood (Glucose)+O2CO_2 + H_2O \xrightarrow{\text{Sunlight}} \text{Food (Glucose)} + O_2

💡Examples

Problem 1:

Identify whether a 'Cloud' is a living thing, a natural non-living thing, or a man-made thing, and explain why.

Solution:

A cloud is a Natural Non-living thing.

Explanation:

Even though a cloud moves and grows in size, it does not breathe O2O_2, does not need food, and cannot reproduce. Since it is found in nature and not made by humans, it is a natural non-living thing.

Problem 2:

A car moves and consumes fuel (food). Why is it not considered a living thing?

Solution:

A car is a Man-made Non-living thing.

Explanation:

A car moves only when operated by a human. It does not grow on its own, it does not breathe, and it cannot produce 'baby cars' (reproduction). It is manufactured by humans in factories.

Problem 3:

Name the gas that living things usually take in during breathing.

Solution:

The gas is Oxygen, represented as O2O_2.

Explanation:

Most living things require O2O_2 to break down food and produce energy for their survival.