Levels of organisation and their functions

• There are 5 levels of organisation;

  1. CELLS
  2. TISSUE
  3. ORGANS
  4. ORGAN SYSTEMS
  5. ORGANISMS
• Cells:

  Cells are the basic unit of structure and function in living things and server a specific function within organisms. Examples: blood cells, nerve cells, bone cells.
• Tissues:

  Tissues are made up by a group of cells, similar in structure and function. They work together to perform specific activities/functions.

  The 4 main tissues in an organism: Connective, Epithelial, Muscle, Nervous.
• Organs:

  Organs are made up of tissues that are working together to perform specific activities/functions, i.e., heart, brain, skin, kidney, lungs, liver and tongue.
• Organ Systems:

  Organ systems are groups of 2 or more organs coinciding to perform a specific activity/function. These could include; the nervous system, circulatory system, urinary system and skeletal systems.
• Organisms:

  Organisms are entire living things that carry out the basic life processes of ->

  1. taking in materials
  2. releasing energy from food
  3. releasing waste
  4. growth
  5. responding to the environment
  6. reproducing

  (In some cases they can be made up of a singular cell like in bacteria.)
• The 4 categories of tissues and their adaptations:

  1. Nervous Tissue -> adapted to support the transmission of electrical impulses.
  2. Epithelial Tissue -> adapted to cover body surfaces, internal and external.
  3. Muscle Tissue -> adapted to contract.
  4. Connective Tissue -> adapted for two functions; to hold other tissues together or to act as a transport medium.