CBSE 8 Science | 2. MICROORGANISMS: FRIEND AND FOE by Pavan | Learn Smarter
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2. MICROORGANISMS: FRIEND AND FOE

Microorganisms, or microbes, are tiny living organisms that are not visible to the naked eye, including bacteria, fungi, protozoa, and some algae. They inhabit diverse environments and can be either beneficial or harmful to humans and the ecosystem. While some microbes play vital roles in processes like fermentation and decomposition, others are responsible for diseases in humans, animals, and plants. Understanding the dual roles of microorganisms is essential for hygiene, food preservation, and medicinal use.

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Sections

  • 2

    Microorganisms: Friend And Foe

    Microorganisms are diverse organisms, playing both beneficial and harmful roles in our lives.

    Learning Practice

  • 2.1

    Microorganisms

    Microorganisms are tiny organisms including bacteria, fungi, protozoa, and some algae that cannot be seen with the naked eye, with some being visible with a magnifying glass.

    Learning Practice

  • 2.2

    Where Do Microorganisms Live?

    Microorganisms, both single-celled and multicellular, inhabit diverse environments ranging from extreme climates to the human body.

    Learning Practice

  • 2.3

    Microorganisms And Us

    Microorganisms play crucial roles in our lives, being beneficial in food production and environmental cleanup, while also posing health risks.

    Learning Practice

  • 2.4

    Harmful Microorganisms

    This section discusses harmful microorganisms that cause diseases in humans, animals, and plants, along with methods to control their spread.

    Learning Practice

  • 2.5

    Food Preservation

    This section discusses the methods and importance of food preservation to prevent spoilage by microorganisms.

    Learning Practice

  • 2.6

    Nitrogen Fixation

    Nitrogen fixation is the process by which certain bacteria convert atmospheric nitrogen into usable nitrogen compounds for plants.

    Learning Practice

  • 2.7

    Nitrogen Cycle

    The nitrogen cycle explains the essential role of nitrogen in living organisms and its continuous movement through the atmosphere, soil, and living organisms.

    Learning Practice

  • 2.8

    Exercises

    This section includes exercises aimed at reinforcing the understanding of microorganisms, their roles, and their classification.

    Learning Practice

  • 2.9

    Extended Learning — Activities And Projects

    This section discusses various activities and projects related to microorganisms, highlighting their roles, applications, and impact in our daily lives.

    Learning Practice

References

NCERT Study Material

Class Notes

Memorization

What we have learnt

  • Microorganisms are invisibl...
  • They can be unicellular or ...
  • Some microorganisms are ben...

Final Test

Revision Tests

Chapter FAQs