Unit 3: A View of the Cell Chapter 3

Bellwork 10/24 If you were absent yesterday come see me List the three statements that compose the Cell Theory. ______________________________________________ 2. In science, a theory is an explanation for some phenomenon that is based on observation, experimentation, and reasoning. One important theory in biology is the cell theory. What kinds of observations led to the development of the cell theory? testing of first vaccines discoveries of fossil bacteria isolations of DNA and RNA microscopic views of plants and animals 3. A cheetah, like those shown below at left, and a paramecium, like the one shown below at right, are both living things. According to the cell theory, what can you conclude about these two very different organisms? A. They are made of many cells. B. They are made of one or more cells. C. They come from the same kind of cell. D. They come from noncellular structures. Bellwork 10/24 If you were absent yesterday come see me Turn in the syllabus, cell theory notes and poster Take out some paper and complete the review on it.

What is the cell theory and how was it discovered? Essential Question Learning Goal What is the cell theory and how was it discovered? Explain what the 3 parts of the cell theory are and describe what events and scientists led to the discovery of the cell theory.

3 parts of the cell theory: 1. All living things are composed (made) of cells. 2. Cells come from preexisting cells (cells reproduce other cells) 3. Cells are the basic, simplest unit of living things.

Scientists How they contributed Hooke Looked at cork under microscope and named what he saw cells Leeuwenhoek First person to view a living organism Schleiden Studied plants and realized they were made of cells Hooke saw Schwann Studied animals and realized they too were made of cells ****Virchow ***Realized all cells come from preexisting cells NOT through spontaneous generation

The invention of the compound light microscope helped to prove the cell theory as it disproved that life happens from spontaneous (random) generation. In other words, people believed that a living thing could be created from a non-living thing and the microscope proved that to be an incorrect belief.

How are prokaryotic cells similar and different than eukaryotic cells? Prokaryotes Both Eukaryotes Include Bacteria Smaller in size Do NOT have a nucleus or membrane bound organelles Contain DNA Unicellular – one cell Contains cytoplasm Contains ribosomes Contains cell membrane Includes plants, animals, fungi, protists Larger in size Have nucleus and membrane bound organelles Complex cells

What is the difference between plant and animal cells? Both Plant Cells Circular/Rounded Shape Lysosomes Centrioles Eukaryotic Multicellular Contain nucleus, Cytoplasm, Cell (Plasma membrane), Rough and Smooth Endoplasmic Reticulum, Mitochondria, Golgi Body Square shaped Contain Cell Wall Contain Chloroplasts Contain Large Vacuole

** Know structures based on looking at a diagram