3.5 Electron microscope and magnification & cells, organs and tissues

What is the magnification equation?

magnification = image size / actual size

How would you convert from metres - millimetres - micrometres - nanometeres ?

What is an electron microscooe and why is it favoured over light microscope?

• have a higher magnification - can see images in greater detail

• have a higher resolution - can see finer details on images

this is because electron beams have a smaller wavelength than light waves

define resolution

the ability to distinguish between two points on an image

Explain why the electron microscope can distinguish smaller cell structures than a light microscope (2)

this is because electrons have a shorter wavelength than visible light, so give greater resolution

Define the following terms:

• cells

• tissues

• organs

• organ system

• organism

• cells - the structural and functional unit of an organism

• tissues - a group of similar cells working together to carry out a specific function

• organs - a group of different tissues working together to perform a particular function

• organ systems - a group of organs with related functions working together to carry out a specific function

• organism - a group of organ systems working together