Bacteria and Viruses- Meaning,Definition,Quiz,Questions,Test
There are few tiny living organisms, if they enter our body ,they can make us sick. These are called germs. These are everywhere, but can’t be seen by open eyes. But these are visible under a microscope, so these are also called microbes. When we breathe in, when we eat food or drink water, these micro-organisms enter our body. But don’t worry our body’s immune system is very strong which keeps a vigil against these invaders & keep us safe most of the time. But there are times, when these germs are very powerful that we fall sick.
There are four major types of Germs:
Bacteria ,Viruses , Fungi & Protozoa
Not all bacteria is bad, some of the bacteria is very helpful for human life. Like the yogurt we eat, it made by bacteria only. Also there is lot of friendly bacteria in our digestive system, which helps in digestion of food. The bacteria, which is not good for human body, is called pathogen. Bacteria can cause cavities, cholera ,plague , pneumonia, sore throat etc.
Viruses can cause Dengue fever, Rabies, Polio, Influenza, measles, mumps ,chicken pox or flu. Viruses can’t survive on their own , they need other living cells to survive. They live inside animals, plants or humans. Where-ever viruses live to survive, they are called hosts. Upon entering living organisms, viruses make copies of them & spread themselves thus causing the host to fall sick.
These are multi-celled organisms like plants. But these can’t make their own food like plants so they are dependent on others to feed themselves .Fungi normally live in damp ,wet & warm places.One of the example of fungi places is in between toes of humans. Young boys & adults get red rashes due to this, this is called Athlete foot. Fungi lives in between toes because these are warm & normally wet due to sweating.
These are one-cell micro-organisms .These love moisture and normally spread diseases through water. Most of the diseases spread by protozoa are result of not using clean water. Use of impure water can cause intestinal infections which can lead to diarrhea or nausea.