Cell Theory Presented by Kesler Science Essential Questions

Cell Theory Presented by Kesler Science

Essential Questions: 1. What is the cell theory? 2. What are similar functions of all cells?

Quick Action – INB Template Cell Theory INB Template 1. 2. 3. 4. Cut out the Template on the solid lines Glue outside tabs into notebook Opens like windows Write notes underneath window panes Robert Hooke What is the cell theory? Matthias Schleiden, Theodor Schwann, & Rudolph Virchow What are the 2 main types of cells?

Cell Theory Cell • Smallest structural and functional unit of an organism • Usually microscopic • Contains cytoplasm and a nucleus enclosed in a membrane • Two main types of cells: 1. Prokaryotic (no nucleus) 2. Eukaryotic (has a nucleus)

Cell Theory Robert Hooke • Observed bark of cork trees under a microscope • Thought the objects looked liked individual rooms in a monastery, which were called cells • Called his discovery cells • Did not know their true function 1665 ells Cork C

Cell Theory Anton van Leeuwenhoek • Developed the microscope lens to see greater magnification • First person to observe bacteria and protozoa (single-celled animal) • Observed and described red blood cells 1670

Cell Theory Mathias Schleiden • Concluded all plant tissues are composed of cells • Declared that the cell is the basic building block of all plant matter. • Sensed the importance of the nucleus of a cell • 1838 ll Plant Ce

Cell Theory Theodor Schwann ell C l a m i n A • Concluded that all animal tissues are composed of cells, too. • Collaborated with Schleiden to form a new theory in biology • 1839

Cell Theory • Schleiden and Schwann’s ideas became known as the cell theory. 1. All organisms are composed of cells. 2. Cells are the basic unit of life. • This theory was as important to biology as the atomic theory was to chemistry. There was one more piece of the puzzle to cell theory. Where did these cells come from?

Cell Theory Rudolph Virchow • Proposed that all cells result from the division of previously existing living cells • This idea became a key piece of the modern cell theory. • 1855

Cell Theory Modern Cell Theory 1. All organisms are composed of cells. 2. Cells are the basic unit of life. 3. All cells come from the division of previous existing cells.

Quick Action – Cell Theory That’s a lot of scientists to remember with very long names. Work with a partner and come up with some sort of device to remember the importance of each one in the development of cell theory. Share your creative device with the class. • Robert Hooke – named the cell base observations on cork bark • Anton van Leeuwenhoek – improved the microscope and observed bacteria and one-cell animals • Mathias Schleiden – all plant tissue is made of cells • Theodor Schwann – all animal tissue is made of cells • Rudolph Virchow – all cells come from preexisting cells

Cell Theory Functions of Cells • Metabolism- chemical reactions inside the cell • Response – perceiving and responding to changes in the environment • Homeostasis – keeping conditions inside the organism within tolerable limits (balanced) m Metabolis Respo nse Homeostasis

Cell Theory Reproduc tion Growth Defen se n Nutritio Functions of Cells (continued) • Growth – increase in size • Reproduction – producing offspring (sexually or asexually) • Nutrition – Obtaining food to provide energy for growth • Defense – protection against enemies

Quick Action – Cell Theory Let’s see how good you memory is. There were 7 cell functions listed on the last two slides. Have your teacher give you another peek at them and then write down as many as you can remember.

Check for Understanding Can you… 1. Recognize that according to cell theory all organisms are composed of cells? 2. Recognise that cells carry on similar functions.