Cells & Heredity: Section 1.1 – Discovering Cells 6 th Science
Cells – the basic units of structure and function in living things The microscope was invented around 1590 and made it possible for people to discover and learn about cells Microscope – an instrument that makes small objects look larger All microscopes have at least one lens Compound microscope – a light microscope that has more than one lens
Robert Hooke – one of the first people to observe cells Anton van Leeuwenhoek – first person to observe bacteria (he called them armalcules, meaning “little animals”) Matthias Schledein – concluded that all plants are made of cells Theodor Schwann – concluded that all animals are made up of cells Rudolf Virchow – proposed that all cells come from other cells
Cell Theory: All livings things are composed of cells Cells are the basic unit of structure and function in living things All cells are produced from other cells
Microscopes Magnification: the ability to make things look larger than they are In a light microscope, lens or lenses magnify an object by bending the light that passes through them Convex lens – a lens that has a curved shape where the center of the lens is thicker than the edges and is called a convex lens Because a compound microscope uses more than one lens, it can magnify an object even more
Resolution – the ability to clearly distinguish the individual parts of an object Electron microscopes – use a beam of electrons instead of light to examine a specimen the resolution of electron microscopes is much better than the resolution of light microscopes