Transcript Section 1.3: Different cells perform various functions

Section 1.3: Different cells
perform various functions
A. Organisms can be classified by their cell type
prokaryotes –
- unicellular organisms with prokaryotic cells
eukaryotes –
- organisms with eukaryotic cells
A. Organisms can be classified by their cell type
Most organisms can be put into one of three domains:
- broad categories of organisms based on their cell type
1) Archaea –
- prokaryotes that mostly live in extreme environments
Hot Springs Archaea were first discovered in extremely hostile
environments, such as this hot spring in Yellowstone National Park
A. Organisms can be classified by their cell type
Most organisms can be put into one of three domains:
- broad categories based on their cell type
2) Bacteria –
- prokaryotes that share some similarities with archea,
but grow virtually everywhere on Earth
A. Organisms can be classified by their cell type
Most organisms can be put into one of three domains:
- broad categories based on their cell type
3) Eukarya –
- eukaryotes, which include multicellular organisms
(plants, animals, fungi and some protists) and unicellular
organisms (some protists)
B. Cells in multicellular organisms specialize
1) All multicellular organisms begin life as a single fertilized
egg.
2) As cells divide, they specialize. Specialization is when
specific cells develop to perform specific functions.
3) The more specialization there is, the more complex the
organism.
C. A multicellular organism is a community of cells
Organisms have different degrees of organization
1) cell
- form the base of the organization. They are the
“members” of the “community”.
2) tissue
- a group of the same cells organized to do a specific job
3) organ
- different tissues working together to perform a
particular function
4) organ system
- different organs and tissues working together
5) organism
- the highest level of organization, an individual living
thing capable of growing and reproducing
The tarsier has many levels of organization in its body.