# Cell measurement: Completed

• Created by: Janelle M
• Created on: 08-06-18 19:55
• Cell measurement
• Light microscopes
• Cells range in size:
• plant cells are between 0.01 mm – 0.10 mm
• animal cells are between 0.01 mm – 0.05 mm
• The human eye can see objects as small as around 0.05 mm.
• A microscope is required to see cells in any detail.
• Microscopes magnify the image of a biological specimen so that it appears larger.
• The type of microscope used in a school laboratory is a compound microscope.
• Calculating the magnification of the microscope
• The compound microscope uses two lenses to magnify the specimen – the eyepiece and an objective lens.
• In most microscopes, there is a choice of objective lenses to use.
• Magnification can be varied according to the size of the specimen and the level of detail required.
• The magnification of a lens is shown by a multiplication sign followed by the amount the lens magnifies, eg ×10.
• Magnification of the microscope = magnification of eyepiece × magnification of objective
• So, if the magnification of an eyepiece is ×10 and the objective is ×4, the magnification of the microscope is:
• magnification of eyepiece × magnification of the objective= 10 × 4= 40
• Calculating the magnification of an image
• Microscopes use lenses to magnify the image of a biological specimen so that it appears larger.