Organisms that cannot be seen through naked eyes and can only be seen through a microscope are called microorganisms. Viruses are microscopic organisms as they reproduce only inside the cells of the host organism, which may be a bacterium, plant, or animal. Fungi either live as parasites or grow on organic matter. It infects wheat plants and lives as a parasite. Vaccines are injected into our bodies to weaken disease-causing microbes. They lead to the production of antibodies in our body which protect us from various diseases in the future.

Microorganisms are classified into bacteria, fungi, protozoa, and algae. As decomposers, microbes are beneficial but some cause diseases, therefore, are harmful as well. Bacteria vary in shape and size. They can be either rod-shaped or spiral. Bacteria are single-celled organisms with a rigid cell wall. 

Viruses are microscopic organisms but they are different from other microbes because they reproduce only inside the cells of the host organism which may be a bacterium, plant, or animal. They can be spread by air, physical contact, and water, etc, and can cause disease in animals as well as plants.

Fungi cannot make their own food. They either live as parasites or grow on organic matter. Fungi spread with the help of spores. In moist, warm environments fungi develops on bread. A pathogenic fungus causes a disease called rust of wheat. But do you know how fungi are developed on eatables? Well, we will learn this in virtual activity.

Vaccines weaken the disease-causing microbes that are injected in our body to trigger the production of antibodies. These antibodies remain in the body for a long time to protect it against the attack of disease-causing microbes. The process of protecting the body from pathogens with the help of vaccines is called Vaccination.

When food is kept for a long time, microorganisms grow on it. They can sometimes produce toxic substances that are poisonous to us. There are various ways to preserve food. Food preservation is the process of treating and handling food to stop spoilage. Pasteurization is the process of heating milk up and then quickly cooling it down to eliminate certain bacteria.