mitosis and microscopes Flashcards
(36 cards)
what are the two different types of microscopes
optical
electron
what is the resolution of the optical microscope
low
what is the magnification og the optical mmicroscope
low
what can thee conditions the sample be in an optical microscope
live
what is magnification?
how many times larger an image is compared to the OBJECT
what is resolution
the minimum distance between two points for them to appear as separate items
what is the equation for magnification
image/actual
what are the two types of electron microscopes
transmission electron
scanning electron
how are electrons usedd to create an image in microscopes
beam of electrons are condensed to create an image
why does an electron microscope have a high resolving power
electrons have a shorter wavelength
what is the magnification like in electron microscopes
high
what conditions can the specimen be observed under in an electron microscope
not living
under a vaccum
what does a transmission electron microscope do?
electrons are transmitted through specimen
what form is the imagee produced in TEM
2D
what conditions does the specimen need to be in TEM
very thin
under vaccum
what are the limitations of TEM
can contain artefacts
sample needs to be thin
vaccum so no live species
what colour is the images from a TEM
black and white
how does a scanning electron microscope work
electrons are beamed on the surface and is sscattered along
what form is thee image in SEM
3D
what colour is the image inn SEM
red
what is the resolving power like for SEM
higher but lower resolving power than TEM
what is the order of units
km
m
mm
micrometre
nanometre
what is the trend for the units
times by 1000
why do we use cell fractionation
to separate individual organelles