Download The Diversity of Cells

Ch 3 S1: The Diversity of Cells
Introduction:
- Cell: The smallest unit that can perform all the
processes necessary for life.
Cells & The Cell Theory:
- Robert Hooke was the first person to see
cells.
- Anton van Leeuwenhoek was the first to see
protists, which he called animalcules, and
bacteria.
- Matthias Schleiden concluded that plant parts
were composed of cells.
- Thedor Schwann concluded that animal
tissues were composed of cells.
- Rudolf Virchow stated that cells could form
only from other cells.
- The Cell Theory was created by Schleiden,
Schwann, & Virchow based off everyone’s
observations. There are 3 parts
o The cell is the basic unit of structure &
function in all living things.
o All organisms are composed of one or
more cells.
o All cells come from other cells.
Cell Size:
- Cells, like a chicken egg, can be large
because they do not have to take in nutrients.
- Most cells are small because they must take
in food and get rid of wastes.
- The area of a cell’s surface compared to its
volume limits the cell’s size.
Parts of a Cell
- All cells have some parts in common.
o Cell Membrane: protective layer that
covers the cell’s surface and acts as a
barrier.
o Cytoplasm: the fluid inside a cell
o Organelles: structures that perform
specific functions within a cell.
o DNA: controls the activities of a cell; may
be enclosed in the nucleus or free-floating
Two Kinds of Cells
- Prokaryote: Single-celled organism with no
nucleus
o PRO means NO!!!
- Eukaryote: Organism whose cells that DO
have a nucleus
Prokaryotes: Bacteria & Archaea
- Bacteria are the most common prokaryotes
- Three types of Archaea: heat-loving, saltloving, and methane-making
- heat-loving and salt-loving are called
extremophiles
o extremophiles are organisms that live in
extreme conditions
Eukaryotic Cells & Eukaryotes
- Eukaryotic cells are the largest cells and are
10 times larger than most bacterial cells
- Have a Nucleus
- Most Eukaryotes are multicellular (ex:
humans, plants, fungi)