Question

why microorganisms are called friends and enemies of human being

Answer 1

your answer----

microorganisms that are helpful for us in any way like to make food, curd, making medicines are called friends microorganisms.
but...

microorganisms that are harmful for us in any way like causing disease, spoiling food etx are called foe or enemies..

thank u!!

Answer 2

some microorganisms are useful for us like fungi, bacteria, etc. bacteria is used to make food items like curd. They are also used to cleaning up of the environment. For example, the organic wastes (vegetables peels, remains of animals, faeces,etc.)are broken down into harmless and usable substances by bacteria. Becteria is used in preparation of medicines. In agriculture they are used to increase soil fertility by fixing nitrogen.
some of them are harmful to us In humans bacteria cause disease as cholera, typhoid