Theory vs Law Law – a fact Theory – an explanation for the fact Example… – Law = If I throw a apple up into the air, it will fall to the ground. – Theory = Gravity

Microscopes Micro = small or tiny Scope = view or to look at Allow us to see small objects clearly 4 Different types

Dissecting Microscope Typically used during dissections 2 separate lens Low power 3-D view w/ greater depth perception Light source shines from above

Scanning Electron Microscope SEM uses a beam of electrons 3-D image of specimen’s surface Black & White Images Can be Colorized by computer 100,000 times magnification Cannot view living organisms

Transmission Electron Microscope TEM transmits electrons through a thin slice 2-D image of specimen slice Higher magnification than light microscope Black & White images Can be colorized by computer

Compound Light Microscope Clearly magnify specimens up to 1,500 times Samples are stained Light source shines up through specimen

Basic Parts Base = Supports the whole microscope Stage = Platform to support the slide Arm = Holds the objectives above the stage Adjustment knob = – Course = Brings objects into rapid focus – Fine = Brings object slowly into focus Eyepiece = Is attached to the nose piece and contains a lens

Basic Parts Nosepiece = Turns to change from one objective to another Objective = Is attached to the nose piece and contains a lens Stage Clips = Holds the glass slide and specimen in place Diaphragm = Regulates the amount of light entering the scope Mirror = Source of light directed into the microscope