Microorganisms - Useful Or Harmful

Nature is beautiful and packed with a variety of species and organisms. After summer vacation, when it’s time to go back to school we observe white patches on your bags and shoes. It’s nothing but living organisms. Yes, there are living organisms other than plants and animals. This third category of living organisms is called microorganisms. They have a long term interactive relationship with humans which are somewhat complicated. At some times they become deadly to other life forms.

Microorganisms: A Domain of Life

Microorganisms are small or microscopic organisms. Also known as microbes, they are tiny creatures. By definition, microorganisms are those organisms which are too tiny to be observed by naked eyes. They may be either unicellular or multicellular organism. Among living organisms, microorganisms are the third domain of classification.  This domain includes all unicellular and multicellular microbes like bacteria, fungi, protozoa, viruses and so on. The white patches on bread in an expired pack or the green patches on the walls of a pickle bottle during the rainy season, etc., are some examples of microbes. The environment is incomplete without these microbes, some of them are important for the survival of other organisms as well.


Life of Microbes

Microbes are omnipresent. The air we breathe, the food we eat, the water we drink, the floor where we stand, each and everything around us is a habitat for some type of microorganism. They are even present inside our body. Microbes are highly gifted living organisms which can withstand extreme conditions like a place as hot as boiling water, or a place as cold as ice.

Some types of microbes like solitary life; they live freely and alone (e.g. Amoeba). While some of them like to live as colonies (e.g. fungi). A wide variety of microorganisms is found in our surroundings with contradictory living characteristics. For example, viruses depend on a host only for reproduction but certain types of bacteria spend their entire life in a host.


Microorganisms can either be helpful, harmless or disease-causing pathogens. Some of them are useful in human welfare while some are harmful and toxic enough to make us ill. Let’s have a glimpse of different types of microorganisms.

  1. Friendly Microorganisms: Every microbe is not a horrific organism. In fact, harmless and useful microbes are more in number than the dangerous ones.  They form a significant part of the ecosystem which takes part in minerals production like nitrogen, gases like oxygen, carbon dioxide, cleaning by action on dead matters etc. The elemental cycle takes place in the environment is a highlighting example of the importance of microorganisms. In various industries, microbes are used purposely due to their role in human welfare. Various industries that use microbes are food and beverages industry, the pharmaceutical industry, etc. The microbes present inside our body that help in digestion are called microflora and the one that increases the fertility of soil are few examples of friendly microbes.
  2. Harmful Microorganisms: Despite all microorganisms are not dangerous and pathogenic, still there exist numerous deadly microorganisms in the environment. They are so small yet enough to cause a disease that may even lead to death. Some of them are free living while some are parasites. These disease-causing microbes are known as pathogens. They may cause acute diseases like common cold to chronic diseases like AIDS.  Other diseases caused by microbes are mumps, polio, rabies, diphtheria, typhoid, cholera, malaria and sleeping sickness, ascariasis and taeniasis, etc.

Therefore microorganisms are helpful and beneficial in various ways and they can also be the reason of death in another way. Hence, stay safe and develop healthy habits.

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Practise This Question

Regarding assertion and reason, choose the correct statement
Assertion [A]: Plant breeding is now increasingly being carried out by using molecular genetic tools.
Reason [R]: Advancements in genetics, molecular biology and tissue culture are being used today for crop improvement.