Introduction to Microorganisms

Microorganisms are tiny living organisms that are invisible to the naked eye and can only be seen through a microscope. They include bacteria, viruses, fungi, and protozoa. Despite their minuscule size, these organisms are incredibly diverse and can be found almost everywhere on Earth, from the deepest oceans to the highest mountains, and even inside our bodies.
Bacteria are single-celled microorganisms that come in various shapes such as rods, spirals, and spheres. Some bacteria are beneficial and play crucial roles in processes like digestion and nitrogen fixation in plants, while others can cause diseases like strep throat and tuberculosis. Viruses, on the other hand, are even smaller than bacteria and need to infect living cells to reproduce. They can cause illnesses such as the flu, the common cold, and more serious diseases like COVID-19.
Fungi include organisms like yeasts, molds, and mushrooms. While some fungi are helpful, such as those used in baking and brewing, others can cause infections in plants, animals, and humans. Protozoa are single-celled organisms that can move independently and often live in water or as parasites. Some protozoa can cause diseases like malaria.
Microorganisms are essential to life on Earth. They help decompose dead organic matter, recycle nutrients, and produce oxygen through photosynthesis. In our bodies, beneficial bacteria aid in digestion and protect against harmful microbes. Scientists study microorganisms to understand their roles in ecosystems, their potential benefits, and ways to combat those that cause diseases. Despite their small size, microorganisms have a massive impact on our world.