Ch.1-4 Tools and Procedures

A Common Measurement System Most scientists use the metric system when collecting data and performing experiments, so that other scientists can replicate their experiments accurately. Metric System-decimal system of measurement, units are based on multiples of 10.

METRIC UNITTOOL USED LengthMeter, Centimeter, Kilometer Ruler, Meter stick VolumeLiter, MilliliterGraduated Cylinder MassKilogram, GramBalance, Scale

Temperature – water boils at C; water freezes at 0 0 C Metric system has been revised to Internationals System of Measurement (SI) A Common Measurement System

Microscopes

Allow light to pass through the specimen and use two lenses to form an image Live specimens may be viewed Dyes may be used to view better images Compound Light Microscope

Electron microscopes Use a beam of ELECTRONS to produce images Specimens must be dead; preserved and dehydrated

Transmission electron microscopes (TEMs)  detail within the cell

Scanning electron microscopes (SEMs)  three dimensional images of the surface

Laboratory Techniques Cell Cultures – group of cells grown in a nutrient rich solution from a single original cell

Cell Fractionation – separate the different cell parts Cells are broken in a special blender Cell bits are added to liquid and placed in a tube Tube is placed in a centrifuge (spins the tube) Cell parts separate with most dense parts settling near bottom

Working Safely in Biology Read the steps and understand the procedure Always follow the teacher’s and textbooks instructions exactly Wash your hands after each activity. You are responsible for your own safety and that of your teacher and classmates!