Life Is Cellular

The Cell Theory Early 1600’s – Two useful instruments were constructed Telescope Microscope

Anton van Leeuwenhoek One of the first people to use a microscope to study nature.

Anton van Leeuwenhoek Using only a single powerful lens, he crafted instruments that could produce magnified images of very small objects.

Anton van Leeuwenhoek His simple microscope enabled him to see things that no one had ever seen before. First person to see tiny living organisms in a drop of water. (1674)

Robert Hooke

Robert Hooke 1665 – English Physicist Used one of the first light microscopes to look at thin slices of plant tissues.

Robert Hooke One of these, a slice of cork. Under the microscope the cork seemed to be made of thousands of tiny chambers. Hooke called these chambers “cells”, because they reminded him of a monastery's tiny rooms aka cells.

Cork Cells

Search For Cells In Other Living Things 1838 – Matthias Schleiden All plants are made of cells 1839 – Theodore Schwann All animals are made of cells 1855 – Rudolf Virchow Studied cell reproduction. “Where a cell exists, there must have been a preexisting cell…”

New Discoveries CELL THEORY The discoveries of these and other biologists are summarized in one of the fundamental concepts of biology. CELL THEORY

Cell Theory All living things are composed of cells. Cell are the basic units of structure and function in living things. New cells are produced from existing cells.

Prokaryotes and Eukaryotes Biologists divide cells into two categories: Prokaryotes and Eukaryotes

Compare and Contrast Eukaryotes Smaller and Simpler Prokaryotes Smaller and Simpler Have Cell Membrane and Cytoplasm No Nuclei Examples (Bacteria) Eukaryotes Larger and More Complex Have Cell Membrane, Cytoplasm, Nucleus, Dozens of Specialized Structures (Organelles) Examples: All Plants, Animals, and Fungi, and Many Microorganisms Some Live Solitary Lives