Download Cells Chapter 1

Cells Chapter 1
The Basic Unit of Life
Section 1 Objectives:
● Explain how life is organized from single cell to
ecosystem
● Describe the difference between unicellular
organisms and multicellular organisms
Organization of Life
From Basic to Complex
Example(s)
cell: basic unit of life
blood cell, muscle cell, skin cell
tissue: group of cells working together
muscle tissue, fat tissue, skin tissue
organ: group of tissues working together
stomach, heart, lungs, skin
organ systems: organs working together
digestive system, circulatory system
organism: anything that can live on its own
you, bacteria, mushroom, fish, tree
population: a group of the same kind of
organisms living together in the same area
all of the Douglas fir trees in a particular forest
community:two or more populations living in the
same area
foxes, oak trees, lizards, mosses and other
organisms living in a forest
ecosystem: the community and all non-living
things that affect it
terrestrial: foxes, oak trees, mosses and rocks
aquatic: fish, frogs, insects, rocks and sand
Organism: anything that can live on its own
Unicellular Organism
● can live on its own
● small
● made up of only a
single cell
Multicellular Organism
● can live on its own
● small & large
● only exists as a group
of cells
Section 2 Objectives:
● State the parts of the cell theory
● Explain why cells are so small
● Calculate a cell’s surface-to volume ratio
● List the advantages of being multicellular
● Explain the difference between prokaryotic
cells and eukaryotic cells
History of Cell Discovery
1665- _Robert Hooke___
●
British scientist
●
Discovered cells when looking at a slice of cork under a microscope
●
thought only plants had cells
1673- _Anton van Leeuwenhoek___
●
Dutch merchant
●
saw animalcules- “little animals” in pond scum through microscope
●
observed animal cells
●
1st to see bacteria
●
discovered that yeast is a unicellular organism
1838- _Matthias Schleiden____
●
German scientist
●
found that all plants are made of cells
History of Cell Discovery
1839- _Theodor Schwann___
●
German scientist
●
found all animal tissues are made of cells
●
wrote the first two parts of the cell theory
1858- _Rudolf Virchow__
●
German doctor
●
found that cells develop from other cells
Cell Theory
● All organisms are composed of one or more
cells
● The cell is the basic unit of life
● All cells come from existing cells
Why are cells so small?
● as cells grow larger they need more food
and have more waste
● as cells grow larger there are not enough
openings in the membrane to allow materials
into and out of the cell
Surface to volume ratio
Formula for Surface Area= lxw (length x width)
Formula for Volume= lxwxh (length x width x height)
Surface to volume ratio
surface area of
one side
1x1 = 1 units2
2x2= 4 units2
1x1= 1 unit2
How many sides?
6
6
6x8=48
total surface area
of cell
6 units2
24 units2
48 units2
Volume
1x1x1 = 1 units3
2x2x2 = 8 units3
1x1x1= 1 units3
1 units3 x 8 cells= 8 units3
Surface-to-volume
ratio
6:1
3:1
6:1
Benefits of being multicellular
● multicellular organisms can grow larger
● cells of multicellular organisms can perform
many different functions
Types of Cells
Prokaryotic Cells
Eukaryotic Cells
no nucleus
nucleus
circular DNA
linear DNA
no membrane covered organelles
many membrane covered
organelles
any cell that is not a bacteria
bacteria