Microbes – Key Points

1. Microbes are microscopic organisms found everywhere on Earth.
2. Besides plants and animals, microbes are the major components of biological systems.
3. Microorganisms mainly belong to:
   • Monera (Bacteria)
   • Protista (Protozoa)
   • Fungi (Yeasts, moulds)
   • Viruses, viroids, and prions (acellular infectious agents)
4. Only microscopic organisms include:
   • Bacteria
   • Protozoa
   • Many fungi (e.g., yeast)
   • Viruses
   • Viroids
   • Prions
5. Microbes are found in:
   • Soil
   • Water
   • Air
   • Inside plants and animals
   • Human body
6. Microbes survive even in extreme environments, such as:
   • Thermal vents (up to 100°C)
   • Deep underground
   • Beneath thick layers of snow
   • Highly acidic environments
7. Major groups of microbes:
   • Bacteria
   • Fungi
   • Protozoa
   • Viruses
   • Viroids
   • Prions
8. Bacteria and many fungi can be grown on nutritive media.
9. They form colonies that are visible to the naked eye.
10. Colony formation helps in the isolation, identification, and study of microorganisms.

Additional NCERT Points (Included from the Next Paragraph)

11. Many microbes are disease-causing (pathogenic).
12. Microbes cause diseases in:

• Humans
• Animals
• Plants

13. Not all microbes are harmful.
14. Many microbes are beneficial and play an important role in human welfare.
15. Microbes have diverse useful applications in daily life and industry.
16. This chapter discusses the important contributions of microbes to human welfare.

NEET One-Liner Facts

• Microbes are ubiquitous (present everywhere).
• Pathogenic microbes cause diseases in humans, animals, and plants.
• Beneficial microbes are used in food production, industry, medicine, agriculture, and environmental management.
• Prions are infectious proteins.
• Viroids are infectious RNA molecules without a protein coat.
• Viruses are obligate intracellular parasites.
• Colonies are visible masses of microorganisms formed on solid nutritive media.