At what magnification do you first notice the ragweed pollen? 2. which is bigger, a rhinovirus or e. coli? 3. based on the magnification, how many of the e. coli can fit into the same space as the head of a pin? 4. about how many red blood cells could fit across the diameter of a human hair (again, look at the magnification scale)?

Microscopes are used to view microscopic or tiny particles that cannot be viewed by naked eyes.

1. Ragweed pollen can be first seen at 100x. Ragweeds are flowering plants. The pollen of ragweed may be an allergen and range in size from 16-27 microns. Pollen grains can be seen with the help of compound microscope.

2. E. coli. is BIGGER than rhinovirus. The size of E. coli. is 0.2 microns in diameter while the size a rhinovirus cell is 0.03 micron in diameter. Thus, it is clear that E. coli. is bigger than a rhinovirus.

3. Based on magnification, approximately 10,000 E.coli. can fit into the same space as the head of the pin. The head of a pin is of 2mm (2000 microns) in diameter and visible with naked eyes while the size of an E. coli. cell is about 0.2 micron in diameter. E. coli. is visible at 10000x. It means that approximately 10,000 E. coli. cells can fit into the head of a pin depending upon the magnification scale.

4. Approximately 100 red blood cells (RBCs) could fit across the diameter of human hair. The diameter of a human hair ranges from 70-100 micron or on an average 75 microns while that of RBC ranges from 6-8 micron. RBC can be seen at 6000x magnification while human hair can be vied at 60x magnification. Thus, 1 RBC is 100 times smaller than a human hair depending upon the magnification.