Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cells: The Basic Unit of Life Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cell Facts *The human body has 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 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 Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings B. All Cells have: 1. Cell membrane 2. Genetic material 3. Cytoplasm Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings C. Cells come in many shapes and sizes Figure 4.2 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 Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Prokaryotic cells : Bacillus polymyxa A Rod shaped bacteria Figure 4.4x1 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 - Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Prokaryotic vs. Eukaryotic Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Prokaryotic vs. Eukaryotic cont. ProkaryoticEukaryotic NucleusNoYes DNAFree floatingIn nucleus Ribosomespresent SizeVery smalllarger Organellesnoyes Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings E. Two Main Types of Eukaryotic Cells: 1. Animal cell & 2. Plant cell 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.