Download DIFFERENT CELLS PERFORM DIFFERENT FUNCTIONS

DIFFERENT CELLS
PERFORM DIFFERENT
FUNCTIONS
DID YOU KNOW, THERE ARE 2-3
BILLION BACTERIA LIVING ON EACH
SQUARE CENTIMETER OF YOUR SKIN?
Most organisms are unicellular.
Some live in unexpected places...
...like hydrothermal vents where there is
extreme heat and little oxygen.
DOMAINS
What is a domain?
1. Archaea (ancient)
2. Bacteria
3. Eukaryote
So, Archaea and bacteria are both prokaryotic
EUKARYOTES
(remember this means they have a nucleus and organelles)
Multicellular
Fungus
Plants
Animal
Unicellular
Protists (more
complex in
structure &
larger than
prokaryotes)
Example of a Protist
Paramecium (has a nucleus and organelles)
Check it out!!
Multicellular Organisms Specialize
Most multicellular organisms consist of
many different types of cells that do
different jobs.
Specialization means that specific cells
perform specific functions.
It is because of this specialization that a
single cell from a multicellular organism
can’t sur vive on its own.
Ex: A white blood cell can fight infection
but it can’t help your body move like a
muscle cell.
A Multicellular Organism is a
Community of Cells
All the specialized cells work together and
interact like a community.
Different types of cells in the body
perform different functions. For example,
some cells take in food and others digest it.
In simple organisms like a sea sponge the
organization of the cell can be quite simple.
If a piece of living sponge is broken off it
will actually regenerate.
TISSUE
In more complex organisms like plants and
animals, cells aren’t only specialized but they
are grouped together in what are called tissues.
A tissue is a group of similar cells that are
organized to do a specific job.
Ex: skin tissue
Other examples...
ORGAN
Different tissues working together to perform a
function form an organ.
Example: the eye or a leaf.
An organ is a more complex level of organization
than a tissue.
ORGAN SYSTEM
Different tissues and organs working
together form an organ system.
Some organisms have only a few organ
systems...
Ex: plant-roots,stems,leaves.
Others have more
Ex: human-11 major systems like the
ner vous system which includes brain,
spinal cord, nerves, and sensory organs
Levels of organization reviewed!
Cell
Tissue
Organ
Organ system
Organism