The Organization of Living Things: Section 4.3
What is an organism?
-
A living thing
Anything that can perform life processes by itself
Unicellular
_____________________ cell
Organisms
Prokaryotes (no nucleus) : __________and archaea
_______________ (have a nucleus) like yeasts, some algae,
some protists
Multicellular
- Made of ______________________ cells
Organisms
- Plants and ____________________
- ______________________ size
- _______________________ life
- Specialization: each cell has a _______________job to do
How are multicellular Level 1: ______________________
organisms
Animals: heart cells, bone cell, brain cells
organized?
Plants: guard cells, root cells
Level 2: ______________________ (a group of cells working
together)
Animals: nerve tissue, muscle tissue
Level 3: ______________________ (a group of tissues working
together)
Animals: heart, stomach, brain
Plants: leaf, stem, roots
Level 4: ______________________ (a group of organs working
together)
Animals: digestive, cardiovascular
Level 5: ______________________ (all of the organ systems working
together)
Examples: human, cat, oak tree, honey bee
Differentiation or
- In ______________________ organisms, cells differentiate or
Specialization
become specialized.
- They will have a ______________________ job to do
Example: Blood cells carry oxygen and muscle cells
contract
- Once they differentiate, they _______________ become other
cells
- Only differentiated _________________ cells can become a
new cell
Example: a leaf cell can become a root cell