October 16, 2015 Page 59 Objective: I can identify the parts of a compound light microscope. Title Microscopes

DNA: Explain the purpose of a microscope.

1665 – Robert Hooke Observed cells in cork. Coined the term "cells”. Cork Cells

1673- Anton van Leeuwenhoek Created a powerful microscope 1 st to see single-celled organisms in pond water

Robert Brown -noticed that pollen grains in water jiggled around called “Brownian motion” -discovered the nucleus Nucleus Human Cheek Cell

Matthias Schleiden A botanist who concluded that all plants are made of cells. Typical Plant Cell

Theodor Schwann A zoologist who concluded that all animals are made of cells. Nerve Cells

Rudolph Virchow A physician who did research on cancer cells and concluded “Omnis cellula e cellula”. “All cells are from other pre-existing cells.”

Microscope Vocabulary Magnification: increase of an object’s apparent size Resolution: power to show details clearly Both are needed to see a clear image

Types of Microscopes 1. Compound Light Microscope –1 st type of microscope, most widely used –light passes through 2 lenses –Can magnify up to 2000x

Ocular lens Objective lenses

Types of Microscopes 2. Electron Microscope –Used to observe VERY small objects: viruses, DNA, parts of cells –Uses beams of electrons rather than light –Much more powerful

Types of Microscopes Transmission Electron Microscope (TEM) –Can magnify up to 250,000x

Types of Microscopes Scanning Electron Microscope (SEM) –Can magnify up to 100,000x

revolving nosepiece stage clips fine adjustment knob diaphragm medium power objective arm stage high power objective light source low power objective coarse adjustment knob tube base incline adjustment eyepiece