magnification Flashcards
what is resolution
the ability of an optical instrument to produce an image that shows fine detail and is able for us to distinguish between two different points
what is magnification
the ability of an object to produce an image bigger than the original objects
features of a light/optical microscope
poor resolution and magnification due to longer wavelengths of light .
cant see smaller organelles
cheap, portable
easy to use
in colour
features of an electron microscope
shorter wavelength so higher resolution and higher magnification
uses beam of fast travelling electrons
sample must be dead or in vacumm so electrons arent absorbed by air or any interference by other molecules
has to be stained as in black and white
features of transmission electron microscope
extremely thin specimen is stained and placed in vacumm
electron gun produces beam of electrons that pass through specimen
some parts of specimen absorb more electrons making them denser
high resolution and magnification
2d cell image in black and white
scanning electron microscopes
specimen dosent need so be thin as electrons are beamed onto the surface which then causes secondary electrons to bounce and scatter and then focus onto the screen
3d image produced
lower resolution and magnification than tem
image size = ?
real size times magnification
why cant optical microscopes produce bigger images
the wavelength of optical microscopes are the same of visible light (400-700nm) which is low and for this reason it cant produce an image smaller than the wavelnght of light
what is the mag and res of a light microscope
mag 1500x res 0.2 micrometres
mag and res of tem microscope
mag more than 1,000,000x res 0.0005micrometres
mag and res sem microscope
mag under 1,000,000x res 0.003-0.005
animal cell organelles that can be seen by light microscope
cell surface membrane, cytoplasm, nuceus , mitochondria, centriole , cytoplasmic granules
plant cell organelles that can be seen by a light microscope
cell wall, cell surface membrane,nucleus,cytoplasm,vacuole , tonoplast, mitochondria, starch grain, chloroplast
animal cell organelles that can be seen by electron microscope
endoplasmic reticulum, nucleoulus,lysosome ,ribosome,nuclear envelopewith pores, golgi apparatus
plant cell organelles that can be seen with electron microscope
er,plasmoderma,nucleoulus,ribosome,
nuclear envelope w/pores,golgi apparatus