Download 3.1 Discovering Cells

Section 3-1
Discovering
Cells
Cells
•
The basic unit of structure and function
of all living things.
– Structure: It’s what makes every living thing.
– Function: It’s what makes every living thing
work.
•
Very small – one square centimeter of
skin’s surface contains over 100,000
cells
Cell Discovery
• Robert Hooke
– One of the first people to observe cells
– Gave them the name cells because they
looked like rooms
• Anton van Leeuwenhoek
– Looked at pond water and observed onecelled organisms he called “animalcules”
– Also looked at tooth scrapings where he was
the first person to see bacteria
The Cell Theory
•
•
•
All living things are made of cells
Cells are the basic unit of structure and
function in all living things
All cells are produced from other cells
Unicellular and Multicellular
• Unicellular – Made of one cell.
• Multicellular – Made of more than one cell.
– Tissue – a group of similar cells
• Ex. A Bunch of Nerve Cells
– Organ – a group of tissues that work together
• Ex. Brain
– Organ System – A group of organs that work
together
• Ex. Nervous System
Nerve Cell
Brain
Nervous System