cell structure 2.0

Question 1

describe how a light microscope works

Answer 1

a beam of light is focussed onto an object and a series of lenses enlarged the object for the eyepiece lenses to pick up

Question 2

benefits of a light microscope

Answer 2

cheap
easy to use
shall
colour images
love specimens

Question 3

disadvantages of a light microscope

Answer 3

weak magnification and resolution
can only view larger structures (whole cells, nuclei, cell membrane)

Question 4

how does a scanning electron microscope work

Answer 4

a beam of electrons scans the object point my point and layer by layer. data is then put in a programme and a 3d image is produced

Question 5

advantages of an electron scanning microscope

Answer 5

high resolution and magnification
can produce 3d images

Question 6

i disadvantages of a scanning electron microscope

Answer 6

sample must be coated in a conductive material like metal
requires skill and training to use

Question 7

advantages of transmission electron microscope

Answer 7

provides high resolution images of internal structures within a structure like organelles within the cell

Question 8

how does a transmission electron microscope work

Answer 8

electrons are fired though a vacuum so the electrons don’t collide with air particles. they then pass through the specimen guided by magnets and are picked up by scanners after deflecting off the specimen and an image is created

Question 9

disadvantages of transmission electron microscope

Answer 9

extensive sample preparation is required like sectioning and staining which could create artefacts
some specimens can not exist in a vacuum
requires specialised training to use

Question 10

what is an artifact

Answer 10

an artificial feature or distortion in the image produced that is not part of the true shape