- Environment refers to all things that surround us. i.e. living and non-living components. These living components are plants and animals.

Components of the environment

 - All the things that make up the environment of a living organism are called components of the environment. 

- The environment is made up of the living and non living components.

The living components

- The living components of the environment comprises of all the living organisms. 

- These living organisms are plants and animals. 


- Plants can be grouped into green and non-green plants.

- The green plants have a green coloring matter called chlorophyll which helps in the formation of plant food.

- Organisms depend on green plants directly or indirectly for food.

- Therefore green plants support life.

- When plants die, they decay and become humus. This process is called decomposition.

- The dead organic matter from plants adds to soil fertility.


- Animals depend on plants for food, shelter or home, medicine, shade and beverages such as coffee and tea.

- When animals die, they undergo decomposition to form humus, just like the plants.

Non-living components of the environment

The non living components include water, soil and air.


Water covers 70% of the earth’s surface.

Water supports life and no living thing can survive without water.

Lack of water in the environment would mean no life hence death of the living components.

  • Water forms a big part of living organisms. The human body for example, is made up of 70% water.
  • Water forms a big part of living organisms. The human body for example, is made up of 70% water.
  • Water is the habitat of many living things such as fish, whales and water plants such as water lily, water hyacinth and arrow roots.
  • Some organisms do not live in water but depend on water for food. Such organisms include the fish-eagles which feed on fish, flamingos feed on tiny water plants and human beings who take fish, whales, lobsters and shrimps as food.


Air is composed of various gases.

These gases and their composition in air are shown in the pie chart below.

All living things depend on air for life.

Animals, for example, need oxygen for breathing in order to stay alive.

Plants on the other hand need oxygen for respiration and carbon-dioxide to produce food in a process called photosynthesis.


  • Soil supports plant life by allowing plants to anchor into it.
  • Soil also provides mineral salts such as nitrates to the plants.
  • Soil is home or habitat to many living things such as earthworms, insects, spiders, millipedes and disease-causing germs such as bacteria.
  • Soil contains air that is used by living organisms which means that a soil without air will not support life. 

Effects of air pollution

Air pollution affects both living and non living things.

Effect of air pollution on living things

Plants: Plants need clean air to be able to grow well and also to be able to make food. Polluted air may affect plants in the following ways:

  • When soot settles on to the plant leaves, they block the stomata of the plant thereby denying the plant air. This suffocates the plant. If all the leaves are covered in soot, the plant may not carry out photosynthesis, respiration and may die.
  • Dust particles, just like soot, settle on the leaves and can cause chocking to the plant.
  • When gases from polluted air dissolve in rain causing acid rain, the rain water may settle on leaves leaving acids on it. These acids damage the leaves of plants by burning them.
  • When acids from rain reach the soil, they make the soil acidic making it hard for plants to grow in it.
  • The chemicals in polluted air can also dissolve in water bodies like rivers, lakes, dams, and oceans making the water poisonous to plants living or growing in the water and around the water.

  • plants by Guilford free library used under CC_BY-SA
  • Water by iPhone walls used under CC_BY-SA
  • Air-pie-chart by ConceptDraw used under CC_BY-SA
  • S3.1.8_-branches by Unknown used under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
  • dust_on_plants_2 by Unknown used under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License

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