Basic Human Needs : Food, Air and Water for Class 2 EVS
The basic human needs are food, air, and water that we get from nature. These are required for the continuity of
life on Earth. Living beings cannot survive without food, air and water.
The following concept will introduce the learners to the dependence of living organisms on nature for food, air and water.
After reading the concept, students will be able to:
- Answer the question—why do we need food.
- State the importance of food for growth and development.
- Give examples of plant sources of food.
- Differentiate between Healthy and junk food.
- Describe sources and uses of water.
- Enlist the sources of water.
Each concept is explained to class 2 students using examples, illustrations, and concept maps. After you go through
a concept, assess your learning by solving the two printable worksheets given at the end of the page.
Download the worksheets and check your answers with the worksheet solutions for the concept Food, Air and water the Basic Human Needs— Food air and water provided in PDF format.
- Food, air, and water are the three necessities for the continuity of life on earth.
- Every living organism needs them for its growth and development.
Anything that gives us energy is called food. Food is vital for our body for the following reasons—
- It provides us with the energy to do work.
- It is required for the growth and development of the body.
- It is needed for the healing of injuries of the body.
- It protects our bodies from diseases.
What Are the Main Sources of Food?
- The food we eat is either obtained from plants or animals.
- Food can be eaten either raw, cooked, or processed.
Plant Sources of Food:
Plants provide us with the following food items—
Animal Sources of Food
We get the following food from animals—
Healthy and Junk Food:
- It is necessary to have good food rich in all the nutrients the body requires for proper growth and development.
- Food with high contents of fat and carbohydrates is called junk food.
Eating too much junk food may lead to obesity.
Examples:Junk foods include pizza, burgers, finger chips etc.
- Air is a mixture of gases that surrounds the earth.
- Air contains life-supporting gases, i.e., oxygen and carbon dioxide, which both animals and plants require.
What Are the Properties of Air?
- Air is colourless and odourless.
- Air has weight.
- Air is a gas and hence occupies the space available.
Cleanliness of Air:
- The presence of clean air in the environment is necessary for all living organisms.
- Air gets polluted if mixed with smoke, dust, harmful gases, etc. Such air, if breathed long, may lead to several diseases.
- Hence, there should be control over the activities that lead to air pollution.
- More trees should be planted so that they can filter the air we breathe.
- Plants are capable of maintaining oxygen levels in the air through the process of photosynthesis.
- Water is an essential component required by living beings to stay alive.
- 70% of our body is made up of water.
Uses of Water by the Living Things:
Some uses of water in our everyday lives are as follows—
- Apart from these, water is used in industries and factories.
- Farmers use water for growing crops.
Sources of Water
Water is obtained from both natural and man-made sources.
Natural Sources of Water:
- Natural sources of water include rivers, lakes, ponds, seas, oceans, and rainfall.
- Rain is the ultimate source of water on earth.
Man-Made Sources of Water:
- The sources of water that humans build are called man-made sources.
Examples:Dams, canals, wells, tanks, etc.
Causes of Water Pollution:
- The water resources get polluted due to human activities. It makes the water unsuitable for use and leads to various diseases.
- The activities that pollute water are as follows—
- Bathing and washing near water bodies.
- Dumping of waste from factories and houses in water bodies.
- Washing off of chemicals used in agriculture in water bodies.
Purification of Water
- Water can be purified by the following methods—
Wastage of Water:
- Water is wasted unknowingly by us. By following the given steps, we can save water—
- Using the water left in bottles for watering plants.
- Closing the taps while brushing our teeth.
- Using buckets instead of the shower for bathing.
- Repairing leaking taps.
Crops: Same plants, when grown on a large scale, are collectively called crops.
Obesity: A disorder caused by the deposition of extra fats in the body.
Did You Know?
- Although the food items like milk, paneer, curd and honey are derived from animals (cattle and honeybees), these are considered vegetarian foods.