2.1 microscopy Flashcards
whats the equation for magnification?
magnification=size of image/actual size
no set units you can use any as long as image and actual size are the sam e unit
define magnification
How much bigger an image appears compared to the original object
define resolution
The ability to distinguish two different objects as seperate
unit conversion
km,m,cm,mm,um,nm
km-1000-m-100-cm-10-mm-1000-um-1000-nm
nm is before um because n for nicole first born child
outline the importance o f microscopes in studying organisms
- cells is unit of life, many organisms are unicellular,
- most cells are to small to see without a microscope,
- subcellular organelles need to seen to understand their function
state/outline the cell theory
- both plant and animal tissue is composed of cellls
- cells are the basic units of all life
- cells only exisit from exsisiting cells
why was the cell theory only developed in the mid 19th century?
prior microscopes were too low magnification to see and identify cell and cell components
why must specimen be thin?
to allow light to pass through so that details can be seen
precaustions to take when using toxic chemicals
avoid skin and eye contact, wear gloves and goggles
scinetifc drawing criteria
- title
- stated magnification
sharp pencil
plain unlined paper
take up whole page
no shadding, continuois lines only
no arrow heads
lable lines paralell to the top of the page
dont cross lable lines
explain why staining is used in microscopy
provides contrast between organels so they can be identified beacuse differnt organells absorb stains differntly
outline the differnece between contrast and resolution
contrast differnce in shade/colour between two objects.resolution is the smallest distane beween objects that can still be distinguished
explain how diffraction limits resolution
light diffracts as it passses through structures light waves spread out/overlap indivdual objects no longer apear seperate causes blurring
why doesent eyepeice graticule have units
its arbitory scale calibrated seperatley for each lense using a stagemicrometer
what is an artefacts in microscopy
visibal structural detail caused by processing the specimen not a feature of the specimen. often bubbles
explain why you would see more detail with electron microscope than a light microscope
electron microscopes use electrons instead of light and electrons have a shorter wavelength than light wich therefore produces images with a higher resolution
why are aertefacts more present in electron scanning microscopy
more sample preperations leads to more damagre to specimen and that damage results in aertefacts
