A scientist who was working on plague-causing bacteria caught the disease despite using weakened strains that were deemed ...

The four components of the blood There are four parts of the blood: red blood cells, white blood cells ... How to observe cells under a microscope Discover how to observe cells using a microscope.

There's three types of microscope: light ... Here's an amoeba engulfing red blood cells and red and white blood cells moving through a tiny blood vessel. And human sperm. A leaf surface at ...