If you want to get a sense of how big various organisms and microorganisms actually are… the University of UTAH has created a really cool tool to zoom in on the microscopic world.
Click Here to Use The Slider on the University of UTAH Website
As you drag the bar on the slider, you gradually zoom in more and more – this is really effective to help understand the actual sizes in comparison to things we are familiar with – Have Fun!
What are Nanometres and Micrometres (micron)? – Click Here