Multicellular Organization

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Multicellular Organization
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I. Tissues, Organs, Organ Systems

• a) Cells are organized into tissues (a group of
  cells that carry out a specific function)

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b) Types of tissues epithelial, connective,
muscle, nerve.
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c) An organ is formed when several types of
tissue interact to perform a specific function
Ex stomach (muscle, epithelial, connective, and
nerve tissue)
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• D. An organ system is composed of a group of
  organs that perform a set of related tasks.
• Ex the digestive system (mouth, esophagus,
  stomach, intestines)
• E. Types of plant tissue dermal, ground,
  vascular.
• F. Types of plant organs roots, stems, leaves,
  and flowers.

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II. Evolution of Multi-Cellular Organization

• Fossil records indicate the earliest cells were
  simple prokaryotes like present day bacteria.
• Organisms dependent on limited organic resources
  reproduced competition of resources cells
  with adaptations evolved (early eukaryotes)

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• Colonial Organizations

• Definition A collection of genetically identical
  cells that live together in a closely connected
  group.
• Example green alga Volvox
• Outer cells use flagella for movement
• Cells involved with reproduction

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• 3. Unicellular organisms Colonial
  organisms True multicellular organisms
• 4. Some believe that plants, animals, and fungi
  evolved from different colonial organisms
  hundreds of millions of years ago.