1. 7-4 the diversity of cellular life

2. Unicellular organisms
Unicellular organisms perform all of life’s essential functions within a single cell.
There are far more unicellular life forms than multicellular ones.
Yeast cell

3. Multicellular organisms
Cell specialization:
Cells develop in different ways to perform different tasks for the whole organism.
Cells communicate and cooperate with each other
volvox
P/S: why do cells of a multicellular organism
need to communicate?
Copepod (1mm)

4. Specialized cells Red blood cells: transport O2
Pancreatic cells: produce enzymes to digest food.
Guard cells open & close the stomata to exchange gases and water in plants.
Islet cells:
pancreas

5. Levels of organization
Within an organism are 4 levels of organization
1. cell
2. tissue
3. organ
4. organ system
WB: what level of organization is our brain?

6. Tissue A group of similar cells that perform a particular function.
Animal tissues:
epithelial, nervous, muscle, & connective

7. Organs
Made of groups of different tissues to perform a specific function for the body
ex: heart, lung, stomach, liver
Heart
liver
PS: discuss the functions of the organs listed
here
lungs

8. Organ system
A group of organs working together to perform a specific function.
Specialization and interdependence is one of the remarkable attributes of living things.
WB: which organs are found in the
digestive system?

9. Summary Today’s topic was……………… A tissue is ………………………
Onion tissue
Today’s topic was………………
A tissue is ………………………
Cells specialize because…………
Cells cooperate because……….