1. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cells: The Basic Unit of Life

2. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cell Facts *The human body has 10 -50 trillion cells * There are millions of different types of cells * Cells are constantly growing and dieing in your body * You were made by the joining of just two microscopic cells

3. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 4.1x A. The Cell Theory: 1. Cells are the smallest unit of life 2. All organisms are composed of cells 3. All cells come from other cells Blood cell Cheek cell Onion cell Nerve cell Muscle cell

4. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings B. All Cells have: 1. Cell membrane 2. Genetic material 3. Cytoplasm

5. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings C. Cells come in many shapes and sizes Figure 4.2

6. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 1. Prokaryotic cells - “before nucleus” - small, relatively simple cells – Found in single-celled organisms – No nucleus –Bacteria D. 2 kinds of cells: Prokaryotic and Eukaryotic

7. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Prokaryotic cells : Bacillus polymyxa –A Rod shaped bacteria Figure 4.4x1

8. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings - have a nucleus - larger than prokaryotes - often multicellular - animal, plant, protist & fungi (everything except bacteria) - membrane bound organelles 2. Eukaryotic cells -

9. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Prokaryotic vs. Eukaryotic

10. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Prokaryotic vs. Eukaryotic cont. ProkaryoticEukaryotic NucleusNoYes DNAFree floatingIn nucleus Ribosomespresent SizeVery smalllarger Organellesnoyes

11. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings E. Two Main Types of Eukaryotic Cells: 1. Animal cell & 2. Plant cell

12. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Review: Cell Quiz Your body is made of trillions of ________. A cell that does not have a nucleus is a ______. A cell that has its DNA free floating is______. The cell theory states that ________. Plant and animal cells are _______ cells.