Science and Our Food Supply: Investigating Food Safety from Farm to Table

Electron Microscope 

An electron microscope uses electrons instead of visible light to produce magnified 

images. It can magnify bacteria a million times their normal size. 

Where Bacteria Come From and How They Grow 

Bacteria are found everywhere, and under the right conditions, they can multiply 

fast! Each bacterium contains all the genetic information needed to make copies 

of itself. Bacteria multiply through binary fission, a process in which the cell’s DNA 

doubles, the cell splits, and two independent cells are formed. Under the right  

conditions, a single bacterium will double with each division — 2 become 4,  

4 become 8, etc. A single cell can turn into millions of cells in a few hours and 

billions of cells within one day! 

This rapid growth is not usually a problem with good bacteria; however, when  

it occurs with “bad” bacteria (a.k.a. pathogens), it is “bad” news. As pathogens  

multiply, some give off harmful toxins or become infectious. If pathogens get into 

our food and multiply, people can get sick.