1. Cell Pre-Quiz True of False? All living things are made of cells. All cells contain DNA. Viruses are a type of cell because they contain DNA. All cells come from other cells. Bacteria cells have a nucleus. Only plant cells have a cell wall.

2. Cell Pre-Quiz True or false? Body tissues are made up of cells. All living things start life as a single cell. All cells are microscopic. A stem cell is a type of cell that can grow into any tissue or organ. Stem cells are found only in a fetus.

3. Unit 2: Cells: Cell Theory (Section 7-1)

4. Biology Standards 1. The fundamental life processes of plants and animals depend on a variety of chemical reactions that occur in specialized areas of the organism’s cells. As a basis for understanding this concept: –C) Students know how prokaryotic cells, eukaryotic cells (including those from plants and animals), and viruses differ in complexity and general structure.

5. Cell Theory 1. All living things are made of cells 2. Cells are basic units of life 3. All cells are made from other cells

6. Why Cells are Important What happens inside cells causes us to be who we are. (Genes) All diseases start at the level of the cell. All growth and life starts from a single cell.

7. Types of cells 1. Prokaryote2. Eukaryote

8. 1. Prokaryotic Cells (Prokaryotes) Simplest, “primitive” cells with: –NO membrane-bound organelles (“little organs”) –NO nucleus: genetic material floats free in cell pro = before karyo = nucleus

9. Ex: Bacteria (Kingdom Monera) 2 Subdivisions: –1. Eubacteria – “true bacteria” –2. Archaea – “ancient bacteria” »Extremophiles: live in harsh environments (hot, acidic, salty)

10. 2. Eukaryotic Cells (Eukaryotes) Unicellular or multicellular Cells contain: – a nucleus (with DNA) – membrane-bound organelles Eu = truekaryo = nucleus Complex internal structure –“Compartments” allow many different chemical reactions to take place simultaneously

11. Examples: –Kingdom Protista – protozoa, algae, amoeba Kingdom Fungi – mushrooms, molds, yeast

12. Kingdom Plantae (Plants)– ranges from moss to flowering plants Kingdom Animalia (Animals) – ranges from tiny worms to humans

13. What about Viruses? -Are they alive? What do you think? CONS –Cannot grow or replicate without host (dormant) –Are not cells PROS –Have genetic material (DNA or RNA) –Can replicate (with host) –Have a protein coat

14. Viruses NOT ALIVE!!! Made of DNA (or RNA) surrounded by a protein coat Viruses are NOT cells & cannot grow –Viruses are extremely small

15. Viruses are extremely small!