Diversity of Life 1

Day 2

What's the main difference between a microscope and a telescope?Microscopes allow us to see

things that are tiny but nearby. Telescopes allow us to see things that are visible size but far away.

Relative Scale & Magnification

Contrasting Case Activity 2bInvestigation 2 – Introduction to the Microscope

Compare ImagesLet's compare a few more images.Can you tell which of these images are from microscopes and which are from telescopes?

Levels of MagnificationAn optical microscope, like the ones used in a science classroom, has different levels of magnification. Below are four images of human blood at different magnifications.

Which image has been magnified the least? The most?

Levels of Magnification

40x 100x 400x 1000x

By placing a clear ruler under a microscope, you can measure the field of view.

Which image has been magnified the least? The most?

Compare Field of View

Compare Field of ViewBy placing a clear ruler under a microscope, you can measure the field of view.

40x 100x 400x

Which image has been magnified the least? The most?

Compare Blood and Field of View

Compare the ruler and blood, which are both magnified to the same level.

400x 400x

How big do you think a red blood cell is?

Compare Optical and Electron

Compare the images of blood below. What are the differences?

1000x 11,000x

Compare Levels of Magnification

• Like optical microscopes, electron microscopes can be used to study non-living objects and well as living cells and organisms.

• In your notebook, draw what you think sugar looks like when magnified through an optical microscope.

• Now draw what you think it looks like at a higher magnification through an electron microscope.

Compare Levels of Magnification

Which image is more magnified? How can you tell?

Optical microscope Electron microscope

Compare Levels of Magnification

Now compare a microscopic organism, a brine shrimp, at different levels of magnification.

Optical Microscope Electron

Microscope

Discussion• Why might an early scientist using a weak optical microscope have believed that nothing could be smaller than a cell?

• When might the higher levels of magnification produced by an electron microscope be helpful to scientists?

• How do scientists today know that there are many smaller levels beyond the cell?