EXPLAIN HOW MICROORGANISMS HAVE AFFECTED HUMAN

Explain how microorganisms have affected human history



Explain how microorganisms have affected human history

For as long as humans have been on this planet, the microscopic life forms that we call microorganisms, or pathogens, have been here too. For all this time they have been multiplying in the soil, in the water, and in our bodies. They are in the mouth, on the skin, and even in important organs. But that is not always a bad thing, because humans could not live without microorganisms. Some microrganisms or "microbes" help digest food, while others produce vitamins.

Most of the time, people and microorganisms coexist peacefully; in fact there are trillions of microorganisms on you right now. Even though some microorganisms are good for us and help us, others can give us diseases. Some diseases only make us sick for a period of time, while others cause incurable and deadly illnesses. Such diseases as cancer and diabetes result mostly from environmental conditions or inherited weaknesses. They are considered noninfectious diseases because one person or animal cannot make another one sick. For a long time, people thought microorganism-born illnesses could be conquered by science. In the late 1900s, new vaccinations and drugs seemed to have them on the run, but microorganisms have bounced back. The drugs that once worked lost their punch, while new diseases keep cropping up. Medicine has made huge strides in fighting microorganisms, but Earth's tiniest creatures remain our biggest foes.

Microorganisms are often called pathogens, which means "the causes of disease," in Greek. The four main types of pathogens are bacteria, viruses, parasites, and fungi. A bacterium is a simple one-celled organism. They are like us because their goal is to survive and prosper. Bacteria are three and a half billion years old. They are the most numerous living thing, and among the smallest. Bacteria can reproduce very fast. One bacterium can multiply into thousands in just a few hours. They attack by destroying healthy cells or releasing poisons. Bacteria can cause a wide range of illness, such as strep throat, cholera, leprosy, pneumonia, tuberculosis, typhoid fever, whooping cough, diphtheria, scarlet fever, tetanus, botulism, and anthrax. Most bacteria can be stopped by antibiotics, but a large number of them can be resistant to drugs. (T. Bier, 2001)

A virus is a lifeless particle that is shaped like rods and spheres. The biggest virus is the size ...