Microbiology: Study of microscopic organisms

Microbiology studies the systematics, morphology, physiology, biochemistry, evolution, ecological roles, and practical uses of microorganisms. Medical microbiology is also part of microbiology.

Different parts of microbiology can be classified into pure and applied sciences.  Microbiology can be also classified by taxonomy, as in the cases of bacteriology, mycology, protozoology, and phycology. There is considerable overlap of the specific branches of microbiology with each other and with other disciplines. Certain aspects of these branches can extend beyond the traditional scope of microbiology

In 1665, Robert Hooke saw that cork was made up of little cubes that he named cells. Later Anton van Leeuwenhoek made the important connection that cells are living things when he saw through his early microscope smallest one-celled organisms. Later Christian Ehrenberg found that protista or bacteria were different kinds of cells. In the late part of the 1800s Martinus Beijerinck showed that there were small particles called viruses.

Another important change in the study of microorganisms came from the discovery of DNA and RNA. This allowed using a vector to change the inside of a cell without killing it. One recent discovery that changed the study of microbiology is the discovery of transposons or jumping genes. Another one is the discovery of animal genes in the cells.