2.1.1 observing cells

describe how to use a microscope

1. locate specimen using lowest power objective lens

2. use coarse focus to focus image clearer under low power objective lens before high power objective lens

3. only use fine focus wheel with the high power objective lens

define magnification

how many times larger something appear appears than its actual size

what is the formula for magnification in a micro

eyepiece lens magnification x Objective lens magnification

define resolution

The smallest distance between two points that can be distinguished as two separate structures

give a disadvantage of light microscopes

magnification is limited due to low resolution because of wavelength or visible light more than beam of electrons

given an advantage of electron microscope

High resolution because shorter wavelength of electrons can distinguish separate structures/lines

give a limitation of electron microscope

Can’t be used to examine Living organisms

what is the formula that relates image size magnification and actual size

I = AM

explain the importance of staining specimens in micropy

Stain provides greater contrast in seeing cell parts that would not be clearly visible by attaching to specific parts/types of cells