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Cells “The Units of Life”

Is every living thing on Earth made-up of cells?

Yes! All living things are made up of cells! A living thing may be made of one cell like Amoeba or Yeast. These are unicellular organisms. Living things might be made up of billions or trillions of cells like an Orangutan or rabbit. These are

multicellular organisms. (We are made-up of about 37.2 Trillion Cells – National Geographic)

Cell Theory (What exactly are cells?)

1. _______________________________________________________________ not from nonliving matter

2. _________________________________________________________ Because every cell can carry out life functions

3. Cells are the basic unit of structure and function in living things The smallest piece of a stomach is a stomach cell… any smaller it wouldn’t be considered a piece of

the stomach The smallest piece of your skin is a skin cell… any smaller it wouldn’t be skin, it could be from any

cell in your body

Exceptions to the Cell Theory

1. ______________________________a. They contain genetic materialb. BUT they need another cell to inject their genetic material into in order to reproduce!

2. The first cell could not have come from a previously existing cell

**Cool Note - Mitochondria and Chloroplasts are cell organelles that contain their own genetic material. They can reproduce independently of the cell

Viruses aren’t cells? Viruses aren’t living… so they can’t be cells! They can’t reproduce on their own; therefore they can’t carry out all

their life functions. They are not cells!

Cells are the basic unit of structure and function in living things

Main Ideas: Cells, Cell Theory, Building Living Things using Cells, Plant Cell, Animal Cell, Cell Organelles and their Life Functions

Key Vocabulary: Cell Theory, Cell, Tissue, Organ, Organ System, Organism, Cell Organelles, Mitochondria, Ribosome, Nucleus, Vacuole, Cell Membrane, Cell Wall, Chloroplast, Cytoplasm, Virus, Eukaryotic Cell, Prokaryotic Cell, Bacteria

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___________________________________________

o According to National Geographic, you have about 37.2 Trillion cells in your body! (not counting microbes)

Cells are the smallest living structures that carry out life processes

If you put cells together, you make more complex structures…

Hmm…

1. What allows cells to carry out their life functions? ___________________________________

2. Before we discuss how cells carry out life functions, let’s see what we can build using cells.

Levels of Biological Organization… plus--Least complex (small)--

Cells Tissues Organs Organ Systems Organism

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Atom

Molecule – two or more atoms together

Organelle – _________________________________________________________

Cell - _____________________________________________

Tissue – _________________________________________

Organ – __________________________________________

Organ System – Group of organs that work together to carry out life functions

Multicellular Organism – Made up of many cells and carries out all life functions--Most complex (big)--

Ok, we know what cells can build but…

BUT what is all that stuff in cells? Hint… these things allow cells to carry out life functions…

_____________________________ (____________________)

So what are these Organelles?

Scientists observed many small structures located inside the cell and they were called Organelles

Organelles literally means “little organs”

Organelles perform all the life functions that keep the cell alive

Just like how our organs perform out life functions

We are_____________________________________________. Therefore we share the same needs as cells!

Cells need food, water, oxygen, waste removal, energy, transport…

We need food, water, oxygen. Waste removal, energy, transport…

Let’s look at Organelles!

Animal + Plant Cells

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Plant Cell Only

Animal Cell Only

1. Which cell might be a muscle cell and which cell might be a skin cell? Why?

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2. If a cell has more ribosomes present in its cytoplasm, what could you predict about this cell?

Compare Animal to Plant Cells

Animal Cells Plant Cells

Does every cell have a Nucleus? _________

Prototype Cells vs. Advanced Cells!

1. Eukaryotic Cells Eu = True Karyon = Necleus

HAS __________________________

Includes all plants, animals and fungi

2. Prokaryotic Cells Pro = before Karyon = nucleus Earliest type of cell

NO _______________________

Relatively small (5 to 10 um)…. Include all bacteria