Discovering Cells Section 1

The Cell Def: basic unit of structure and function in living things

Cell and Structure Structure of living organisms are determined by the variety of ways cells are put together   Red Blood Cells Nerve Cells Skin Cells

Cells and Function The processes that enable a cell to live, grow, and reproduce are obtaining Oxygen Food Water Getting rid of waste

Size of a Cell Cell and Structure

Scientist involved with Microscopes and the Cell Hooke (1665) Van Leewenhoek (late 1700s, early 1800s) • Schleiden (1838) • Schwann (1839) • Virchow (1858) • Observed Cellular nature of cork slices •Lenses & Microscopes • Plant cells • Animal cells • All cells from preexisting cells

The Cell Theory Explains the relationship between cells and living things States: All living things are composed of cells Cells are the basic unit of structure and function in living things All cells are produced from other cells

Microscope An instrument that makes small objects look larger.

Magnification and Lenses Condition of things appearing larger than they are Magnifying glass: Consists of a convex lens (center is thicker than edges) Light passes through and into the eye, image is magnified revealing more detail of object

Compound Microscope Uses two lenses at once: One fixed in the eyepiece Second lens chosen from a group on the revolving nosepiece Each has different magnifying power Total magnification = magnification of the 2-lenses multiplied together

Microscopic Objects Measuring Resolution Using a metric ruler, measure the size of the circular field in millimeters as you look through the lense Def: the ability to distinguish two objects from each other Improves as magnification increases.

The Electron Microscope Uses a tiny beam of particles called electrons to produce magnified images

Electron Micrographs

Parts of the Microscope

Parts of the Microscope Answers