1. Specialized Cells to Organ Systems

2. Recall Cell Theory -all living things are made up of cells (one or more) -cells are the smallest unit that can support life -biogenesis (living cells only come from other living cells

3. Unicellular Organisms “uni-” = one Include bacteria and protists that will be studied later Single cells that can still do everything they need to stay alive Benefits over multicellular organisms: – Need fewer resources – Can live in harsher conditions

4. Multicellular Organisms “multi-” = more than one Plants, animals, and most fungi are multicellular Start as a single cell  many cells  cells differentiate (change) into different types of cells  cells group together

5. Cell Specialization As multicellular organisms develop, their cells differentiate (change & separate) and form levels of organization Why it Matters: so Humans (we are multicellular) can have different kinds of cells, tissues, organs, and organ systems

6. Advantages of Multicellularism Each cell in a multicellular organism does not perform all the bodily functions, nor is it required to perform all of it’s life functions Each type of cell specialises in performing one particular function. Different functions in a multicellular organism can be performed at the same time by division of labour.

7. Division of Labour -Sharing different functions in an organism among its cells, tissues, organs and systems – Ensures smooth running and effective working of the different parts in an organisms as well as the organism as a whole.

8. Levels of Organization 1 st Level: Cells 2 nd Level: Tissues 3 rd Level: Organs 4 th Level: Organ Systems Cells  Tissues  Organs  Organ Systems

9. Level 1 : Cells Cells can be specialized (have a certain function) Function = job Function is related to the cell structure Structure = how parts of the cell are put together – Shape – Material it’s made from Structure of a brain cell is different from muscle cell

10. Level 2: Tissues Tissue = group of cells that work together to do a specific job Ex: Heart muscle tissue is made of heart muscle cells Animals have 4 types of tissue: nerve, muscle, connective, Epithelial (protective) Plants have 3 types of tissue : Vascular (transport), Epidermal (protective), ground (many books refer to leaf or photosynthetic as a 4 th tissue)

11. Level 3: Organs Organ = structure that is made up of 2 or more tissues working together to get a specific job done. Ex: Stomach – muscle tissue moves food, special tissues make chemicals to digest food, connective tissue holds stomach together, nervous tissue sends messages back and forth between the stomach and brain

12. Level 4: Organ Systems Organ system = group of organs working together to perform a specific function Each organ system has a specific job Ex: Digestive system is made of several organs including the stomach and intestines

13. Main Organ Systems in a Human Respiratory system Digestive system Blood circulatory system Skeletal system Muscular system

14. Organism -originally defined as “something made of organs” the word organism now refers to a living thing

15. Structure of Animals Cells -basic unit of an animal’s structure -become specialized _______________________________ Tissues -made of cells that work together to perform a specific function __________________________________________ Organs -made of different types of tissues that work together to perform a specific function ____________________________________________________ Organ Systems -made of organs that work together to perform a specific function _____________________________________________________________ Organisms

16. Assignment Log onto the great plains website (see instruction page attached) Try out the cells to systems webquest (easier on the website you can click on the links and type in the answers.)