Notes: Natural Resources | Science & Pedagogy Paper 2 for CTET & TET Exams - CTET & State TET PDF Download

Introduction

Resources obtained from the environment are known as natural resources. On one hand, natural resources are fast depleting because of overexploitation by humans and on the other hand, the earth is becoming a big dumping ground for waste generated by the activities of the rapidly growing human population.

These resources can be further divided into two:

• Abiotic resources
• Biotic resources (living natural resources)

Abiotic Resources

Abiotic resources are the physical or chemical non-living resources of our nature. For example land, water, Energy, Metals and Petroleum and Natural gas.

• Water: The natural water bodies include oceans, seas, and surface water bodies such as rivers, lakes, waterfalls and ponds. Almost 80% of the earth’s fresh water remains frozen at a higher latitude and on mountains tops in the form of glaciers and ice sheets. Only 20% is available in liquid form. The primary source of water on land is the rainfall. Water is an essential requirement for all living beings.
• Energy: The prime source of energy is solar radiation. Coal, as you know, has been formed from vegetation which grew millions of years ago, fell and got trapped in sediments. Under immense pressure and intense heat for years, tress and vegetation buried in the sediments transformed into coal. Coal is used as a fuel for cooking, for running locomotives, furnaces industries and generating electricity. Coal is also used for extraction of metals and minerals and in thermal power generation.
  Energy is also harnessed from the sun (solar energy), wind (wind energy), animal excreta (biogas), sea (tidal energy) and radioactive minerals (nuclear energy).
• Petroleum and natural gas: Petroleum and natural gas are also fossil fuels. Petroleum probably originated from marine animals that lived during past geological periods, just as coal was formed from vegetation. Petroleum and natural gas are obtained from deep inside the earth and they are non-renewable energy resources. Petroleum products are used for running automobiles, steamers, aeroplanes and for making plastics and fertilizers.
• Metal ores or minerals: Metal ores are chemical compounds (salts) of metal such as Aluminium, iron, copper, lead, zinc, manganese etc. These ores are found as deposits under the earth's surface. Aluminium is used to make utensils, parts of vehicles, aircraft, and spacecraft. Iron and its alloys are used for making ornaments, heavy machinery, railway engines, railway lines and a wide variety of articles. Copper is used for making industrial containers, electric wire and also used in electronics and telecommunication industries. Alloys such as brass and bronze contain copper.
• Land: Many organisms, including humans live on land. Landforms just approximately 29% of earth’s surface includes mountains, rocks, deserts, swamps, forests and grasslands. Humans use the land for growing crops that provide them with food. They also need land to build shelters, roads and cattle sheds. The need for land usage is steadily growing.

Biotic resources

These include plants, animals and microorganisms.

• Plants: The natural food resources included in the human diet are the various cereals, legumes, vegetables and fruits. Humans cultivate plants to obtain good grains, pulses, spices, vegetables, fruits, sugar and oil from them. Fibre yielding plants are grown by us to obtain cotton, jute and flex etc. Industrial raw material such as rubber, timber, and resins are irreplaceable plant products.
• Animals: Goat, fish, eggs, poultry, prawns and crabs are the source of food for human beings. Horses, bullocks, elephant, oxen, camels, donkeys, yaks etc. are used for transportation and are known as draught animals. Yaks and sheep yield wool for woollens. Silkworms are reared for silk.
• Microorganisms: They provide antibiotics essential for the medicational purpose. Their use in fermentation and in breweries is an age-old practice. Microbes are responsible for processing waste and dead plants and animals.