Sit in Assigned Seats DO NOW (silently, 5 min) Fill out the chart on your guided notes in the BEFORE column. Be prepared to defend why you agreed or disagreed. Agree/ Disagree (BEFORE) STATEMENT All bacteria that are alive today have come from pre-existing bacteria. The smallest unit of life is a carbon atom because all living things are carbon-based life forms. Plants and animals are made of cells but fungi and bacteria are not. All cells are microscopic (you need a microscope to view them). To be considered a cell the only two things it needs are a cell membrane and cytoplasm. Agree/ Disagree AFTER
I m going to show you a short 15 second clip of a bird behavior. I want you to write down on your guided notes what you observe is happening. Make sure to observe what the birds surrounding looks like. http://www.youtube.com/watch?v=ln2xq8fcni8
Now in your groups, each person will have 15 seconds to share out what they think is happening. You will then come up with a theory as a group.
The process you all just went about is how scientists will create theories. Of course it takes a little more time and experimental design, but building ideas off each other is how the game is played.
The Cell Theory
How Small is a Cell? http://learn.genetics.utah.edu/content/be gin/cells/scale/ If cells are so small, how did humans ever find them?
What changed how we thought of life? Microscopes!
History of the Microscope 1590 first compound microscope
Types of Microscopes 1. Compound Light Microscope 1 st type of microscope, most widely used light passes through 2 lenses Can magnify up to 2000x
Ocular lens Objective lenses
Types of Microscopes 2. Scanning Electron Microscope (SEM) Used to observe VERY small objects: viruses, DNA, Uses beams of electrons rather than light 3D Images
SEM Images http://research.amnh.o rg/pbi/graphics/descrip tion/i_scanning_microg raph_phymatopsallus_ri nconae.jpg
Types of Microscopes Transmission Electron Microscope (TEM) Can magnify up to 250,000x Can see inside of cells.
I. What is a cell? A cell is a structure containing cytoplasm enclosed by a cell membrane.
II. What did people believe before cells were discovered? Theory of Spontaneous generation = that living things can come from non-living things Ex maggots from meat; or mice from hay;
Franscesco Redi Says NAY!!! In 1668, the dreamy Italian doctor, Francesco Redi, proved maggots came from flies, and were not spontaneous generated from meat.
Redi s Hypothesis: Flies produce maggots. Three Separate Experiments: THREE GROUPINGS OF MEAT IN JARS. GROUP 1: Open to the air. GROUP 2: Gauze covering, so that air could enter, but no flies could enter. GROUP 3: Sealed to air.
Redi s Hypothesis: Flies produce maggots. Three Separate Experiments: THREE GROUPINGS OF MEAT IN JARS. GROUP 1: Open to the air. GROUP 2: Gauze covering, so that air could enter, but no flies could enter. GROUP 3: Sealed to air.
How we discovered cells. In 1665 Robert Hook looked under a microscope and this is what he saw This is a picture of what a piece of dead plant looks like under a microscope. What observations can we make? What would you call these?
How we discovered cells. In 1838 Matthias Scheliden looked under a microscope and this is what he saw This is a picture of living plant tissue. What observations can we make? What inference can we make about plants? Are they made of cells?
Theodore Schwann The next year, Theodore Schwann looked under a microscope and this is what he saw This is a picture of living nervous tissue
How we discovered cells. The next year, Theodore Schwann looked under a microscope and this is what he saw This is a picture of living animal tissue. What observations can we make? What inference can we make about animal tissue? Are they made of cells?
III. What are the 3 Parts of the cell theory? 1. All cells come from pre-existing cells 2. Cells are the basic unit of life 3. All organisms are made of cells. The Cell Theory was used to disprove spontaneous generation.
. How does the everyday use of the word "theory" influence how people think about scientific theories? Write this question down, and answer in your notes.
VIDEO BREAK https://www.youtube.com/watch?v=4opbylwh9du
CELL RECAP!! In your groups, decide which statement from the Cell Theory best fits the pictures I am going to show you!
All organisms are made of cells.
All existing cells are produced by other living cells.
The cell is the most basic unit of life.
Closing. Let s Discuss our answers Modify your anticipation guide answers Take our exit ticket! BEFORE STATEMENT AFTER All bacteria that are alive today have come from pre-existing bacteria. The smallest unit of life is a carbon atom because all living things are carbon-based life forms. Plants and animals are made of cells but fungi and bacteria are not. All cells are microscopic (you need a microscope to view them). To be considered a cell the only two things it needs are a cell membrane and cytoplasm.
Practice Worksheet 10min alone 5min with a partner Go back to seat when timer goes off
Clear Off Your Desk