Microorganisms: Definition, Classification, Examples



Today we discuss Microorganisms: Definition, Classification, and examples: A microorganism or microbe is an organism that’s microscopic. The examination of microorganisms is known as microbiology. Microorganisms could be a microorganism, fungi, archaea, or protists. Microorganisms usually are not comparable to one another, they differ not solely in measurement but in addition to construction, habitat, metabolism, and several other different traits. 

Because the title suggests these organisms which are seen via a microscope or microscopic organisms are referred to as microorganisms or microbes. They’re discovered throughout us and you may be amazed to know that they’re discovered inside our bodies additionally. So, we are able to say that microorganisms are so small that normally, we require a microscope to see them. Leeuwenhoek’s invention of the microscope quickly led Louis Pasteur to comprehend that many ailments had been brought on by microorganisms – and to follow pasteurization, which kills microorganisms and makes our meals merchandise suitable for eating as we speak.

Now, we all know that microorganisms are accountable for many issues that occur on the earth around us. They stay in the water, in the soil, on the skin, and within the digestive tracts of animals. Because of this, all dwelling issues will need to have immune programs – whereas many microorganisms could be useful to them, some could be dangerous and trigger illness.

Classification of Microorganism

There are numerous varieties of microorganisms :

Bacteria: Bacteria are the commonest microorganism that we hear about most in our day-by-day lives not it! They’re a member of prokaryotes. They don’t have a nucleus contained in the cell and don’t comprise organelles. So, primarily they’re specialized mobile organs. Bacteria include two courses specifically Gram-positive bacteria which consist of a thicker cell wall and one other is Gram-negative which have a thinner layer that’s sandwiched between an internal and outer membrane.

Archaea: Archaea, or archaebacteria, had been as soon regarded as a part of the microorganism household. Archaea could be present in lots of similar locations as bacteria – in water, in soil, and inside our digestive tracts, the place they assist us to remain wholesome. Nonetheless, archaebacteria can be present in some uncommon locations – many are capable of staying in environments that are extremely popular, very chilly, very acidic, or very salty.

Protozoa: Protozoa are various groups of unicellular eukaryotic organisms. Like bacteria and archaea, they’re single-celled; however, their cells resemble these of animals and crops greater than these of bacteria or archaea. A number of harmful human ailments together with malaria, toxoplasmosis, giardia, African “sleeping illness,” and Chagas illness are brought on by protozoa.

Fungi: Although some microscopic fungi can infect people identical to bacteria or protozoa, there’s one microscopic fungus that almost all people like lots: yeast!

Yeast is the fungus that’s accountable for making baked items rise; and for producing alcoholic drinks resembling beer, wine, and liquor. They feed on sugars present in meals and convert it into carbon dioxide – and, sure, ethyl alcohol. The carbon dioxide could make our bread and desserts fluffy, and the alcohol can construct as much as intoxicating ranges if yeasts are bottled with an excessive focus on sugar.

Fungus consists of pathogens that may trigger illness in crops. In truth within the meals business, for manufacturing of beer, and so on. fungi are used.

Viruses: In accordance with varied consultants viruses usually are not dwelling organisms. They include a nucleic acid that’s DNA or RNA and a protein coat. Principally, a virus requires a number of cells for replication. The virus enters human beings and enters the cell in the place they replicate.

It relies upon the immune system of the physique. If the immune system is weak then the virus could have an effect on the human being and should trigger ailments like a standard chilly, influenza, and so on. In truth, some viruses could trigger everlasting and irreversible harm to the cells of human beings for instance HIV.

Examples of Microorganism

streptococcus micro organism

Streptococcus is a bunch of microorganisms that cause sickness in people. As the title suggests, streptococcus microorganism is the reason for strep throat – and also can trigger scarlet fever and, not often, pores and skin and muscle infections.

Malaria Parasite (Plasmodium)

Malaria is the deadliest illness to people on Earth as we speak. Transmitted from host to host by mosquito bites, it causes critical signs resembling fever, hemolytic anemia, and convulsions because the Plasmodium parasite reproduces contained in the host’s physique.

Lactobacillus rhamnosus

If Streptococcus is an “unhealthy” bacterium, Lactobacillus is a “good” kind of bacterium. Lactobacillus is discovered in lots of yogurts. Some folks even take extremely concentrated doses of Lactobacillus within the type of “probiotic” capsules or capsules in hopes of staying wholesome!


Cyanobacteria was one of many first varieties of life to evolve on Earth. Cyanobacteria can flip carbon dioxide into oxygen – and it will possibly flip unusable inorganic nitrogen into natural varieties that can be utilized to make proteins and extra!

Cyanobacteria was one of many first organisms on the planet, it seemingly needed to do these issues for itself – there have been no different nitrogen-fixing organisms around to companion up with.

Cyanobacteria is one other nice instance of a “good” microorganism to which people owe an important deal!