The Living Environment

1. The Living Environment Chapter 9: Laboratory Skills

2. Tools for Measurement • Key Terms • Metric ruler- used to determine the length of an object, using cm or mm. • Graduated cylinder- used to measure a liquid’s volume • Volume- the space a liquid occupies • Mass- the quantity of matter in something

3. Tools for Measurement Continued • Balance- a tool that measures mass by comparing an object of unknown mass with an object of known mass. • Electronic balance- measures mass automatically

4. Microscope Skills • Key Terms • Microscope- a tool that uses a lens or a combination of lenses to make an object easier to see • Magnification- the ability of a microscope to make an object appear larger • Stereoscope- also called a dissecting microscope, has 2 ocular eye pieces and one or more objectives

5. Additional Laboratory Techniques • Electrophoresis- a very powerful tool that is widely used by scientists in many disciplines • Chromatography- a technique used for separating mixtures of molecules • Stains- used to make cell structures more visible • Indicator- a substance that changes color when it contacts certain chemicals

6. Identifying Cell Parts • Nucleus- round, dense, and dark. Can be found anywhere in the cell • Cytoplasm- fills the cell. Can be clear or grainy in cells. • Cell membrane- surrounding the cytoplasm. Outer boundary in animal cells, between cell wall and cytoplasm in plant cells

7. Identifying Cell Parts Continued • Cell wall- on the outside of the cell membrane in plant cells • Chloroplasts- green, oval shaped, found in the cytoplasm of plant cells • Vacuoles- can be clear areas in the cytoplasm. In plant cells, they fill most of the inside of the cell. • Chromosomes- dark staining and threadlike