Class 8 Science – Chapter 2

Microorganisms: Friend and Foe

🔹 What are Microorganisms?

Microorganisms are very tiny living organisms which cannot be seen with the naked eye. They can be seen only with the help of a microscope.

These organisms are present everywhere – in air, water, soil, inside plants, animals, and even inside our bodies.

🔹 Discovery of Microorganisms

Microorganisms were discovered by Antonie van Leeuwenhoek using a simple microscope. He was the first scientist to observe bacteria and protozoa.

🔹 Where are Microorganisms Found?

• In air and water
• In soil
• Inside the bodies of plants and animals
• In extreme conditions like hot springs and icy regions

🔹 Size of Microorganisms

Microorganisms are extremely small. Thousands of microorganisms together may not be visible to our eyes. Because of their small size, special instruments like microscopes are required to study them.