Magnification and Resolution

Question 1

Calculation

Answer 1

Magnification= size of image / actual size
AIM

1um = 1000nm
1mm = 1000um

Question 2

Magnification

Answer 2

• Magnification is how many times larger the image is than the actual size of the object being viewed.
• Interchangeable objective lenses on a compound light microscope allows a user to adjust the magnification.

Question 3

Resolution

Answer 3

• Resolution is the ability to see individual objects as separate entities.
• Resolution is limited by the diffraction of light as it passes through the samples and lenses. Light reflected from individual structures can overlap due to diffraction.
• Can be increased by using beams of electrons which have shorter wavelengths than light.

Question 4

Electron microscopy

Answer 4

• Beam of electrons with wavelength less than 1nm is used to illuminate the specimen. More detail of cell ultrastructure can be seen.
• Specimens can be damaged by electron beam as prep process is very complex which causes a problem with artefacts (structures that are produced due to the prep process)
• TEM= transmitted through; SEM= reflected electrons from surface are collected
• Inside of E.M is a vacuum to make electron beams travel in straight lines.