Big Idea – Life is a result of interactions at the molecular and cellular levels. Guiding question for lesson: What is a cell? Think, pair & share What is a cell? Cells They are the smallest piece or unit of life. Development of the Cell Theory Video People have known about the existence of cells for only the last 300 years or so Onion skin cells Early microscopes allowed scientists to discover what we now take for granted: All living things are made up of cells Cells are fundamental units of life Paramecium Cell Theory 1. All living things are made of one or more cells 2. Cells are the basic units of life (the smallest pieces). 3. All cells come from existing cells. Two types of cells Prokaryotic cell 5 µm Eukaryotic cell 100.0 µm Prokaryotic Cells Smallest living cells Simple internal structure Lack membrane-bound organelles (like mitochondria, chloroplasts etc. Pro = Before Karyon = nucleus They have NO nucleus DNA in a Nucleoid (a region inside the cell that contains most of the DNA) ALL BACTERIA ARE PROKARYOTIC Eukaryotic Cells Eu = True Karyon = Nucleus The DO have a nucleus Have membrane-bound organelles Nucleus, vesicles, mitochondria, Golgi body Organelles function as a “team” to carry out the essential functions ALL PLANTS, ANIMALS, FUNGI AND PROTISTS Prokaryotic Cells Eukaryotic Cells Very small in size Fairly large in size No nuclear membrane surrounding nuclear material Nuclear membrane surrounding nuclear material Nucleolus absent Nucleolus present Membrane bound organelles absent Membrane bound organelles present Cell division by fission or budding Cell division by mitosis or meiosis Big Idea – Life is a result of interactions at the molecular and cellular levels. Guiding question for lesson: What is a cell?
