Leaving Cert Biology Section 2 1 Cell structure

Leaving Cert Biology Section 2. 1 -Cell structure The Microscope

Leaving Cert Biology Section 2. 1 -Cell structure Today’s objectives • To get familiar with the microscope • To learn the difference between a light microscope and an electron microscope

Leaving Cert Biology Section 2. 1 -Cell structure Homework • Write up today’s experiment in your labbook– title, materials, procedure, Results, conclusions

Leaving Cert Biology Section 2. 1 -Cell structure The light microscope Rough Focus Wheel Fine Focus Wheel Eyepiece Nosepiece Objective lens Clip Stage Diaphragm Mirror / Source of light

Leaving Cert Biology Section 2. 1 -Cell structure The light microscope Light rays pass through the sample, through the lens and then into your eyes! Up to x 1000 times magnification! total magnification = magnification of eyepiece lens x magnification of objective lens

Leaving Cert Biology Section 2. 1 -Cell structure The light microscope- images An egg cell Red blood cells

Leaving Cert Biology Section 2. 1 -Cell structure Transmission Electron Microscope • A beam of electrons is passed though the sample, and focussed using magnets onto the specimen. • The image can be viewed on a TV screen. Up to x 500, 000 times magnification!

Leaving Cert Biology Section 2. 1 -Cell structure Electron microscope images A human hair Salmonella bacterium Pollen A nerve ending