Cells and Microscopy The Big Questions How do

Cells and Microscopy

The Big Questions • How do we even know cells are even there? • What has advanced our understanding of cells?

Specification Link • Describe how plant and animal cells can be studied in greater detail with a light microscope • Demonstrate an understanding of how changes in microscope technology have enabled us to see cells with more clarity and detail than in the past, including simple magnification calculations

Light Microscopes • Microscopes let us see things that we can’t see with the naked eye. • Light microscopes were invented in the 1950’s. They let us see things like nuclei, chloroplasts and mitochondria.

PARTS OF A MICROSCOPE Eyepiece Lens Handle Objective Lens Focusing Knob Stage Mirror Test

Microscopes Electron Microscopes Light Microscopes • Invented in 1590’s. • Invented in the 1930’s. • They let use see things like nuclei, • Let use see much chloroplasts and smaller things in mitochondria. more detail like the internal structure of mitochondria and chloroplasts.

Magnification • The length of the magnified object = Length of the object X Magnification • Rearranging this tells us that Length of object = Length of the magnified object The magnification

You need to learn those equations!!

1. A scientist looks at a cell with a microscope that has a magnification of times 40. The cell is 0. 1 mm long. Calculate the size of the magnified image. (2) 2. The electron microscope can magnify images. . . . . than the light microscope. (ii) The diagram shows a sperm cell that has been magnified 100 000 times. Calculate the actual length of the sperm cell.