4.1.1.5 Microscopy

what is magnification

how many times bigger the image is than originally

what is resolution

the minimum distance where you can distinguish between two points- higher resolution gives a sharper image

Formula for magnification

Magnification = image size / real size

formula for image size

image size= magnification x real size

when finding out image size, magnification and actual size what is important to know

units must be the same

Units for nanometres

NM

Units for millimetres

mm

Units for micrometers

um

units for decimetres

dm

why is iodine used when looking at onion cells.

Iodine solution is used as a stain. A stain is used to highlight objects in a cell by adding colour to them

Parts of a microscope

eyepiece, objective lens, fine adjustment know, course adjustment knob, stage, stage clips, diaphragm

Light microscope -16665

Used to view tissues,cells and large sub cellular structures

Electron microscope-1930s

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Uses electrons opposed to light to form ab image because the electrons have a smaller wavelength than light

Snacked scientists to view deep inside sub-cellular structures

Produces 3D images

2D images detailing organelles

much higher magnification and resolving power than a light microscope. This means that it can be used to study cells in much finer detail. This has enabled biologists to see and understand many more sub-cellular structures.

magnification of a light microscope

Magnification of the eyepiece lens x magnification of the objective lens