Introduction to the Cell

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Introduction to the Cell

• Paramecium is a single-celled organism

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• Humans are multi-cellular organisms

Stevie Wonder under the microscope, skin cells
Stevie Wonder
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Cell Theory

• Cell theory states that
• All living things are composed of cells
• Cells are the basic units of structure and
  function in living things
• New cells are produced from existing cells

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• All cells share certain characteristics
• Cell (Plasma) membrane thin, flexible barrier
  around the cell
• Cytoplasm material inside the cell membrane
  which contains many important things

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Prokaryotes vs. Eukaryotes

• All cells are divided into these two groups.
• The main difference is that prokaryotes do not
  have a nucleus and eukaryotes do.

Familiar prokaryotes include bacteria. Most
other cells are eukaryotic.
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Prokaryotes
Eukaryotes are divided into two categories (plant
and animal)
Cells
Eukaryotes

• Plant cells
• Cell wall
• Vacuole
• Chloroplast

• Animal cells
• Lysosomes

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Examples of different types of cells

• Prokaryotic cells
• Example bacteria
• Eukaryotic cells
• Example cells in the human body
• Example plant-like protists (algae) and
  animal-like protists (such as paramecium)