Levels of organisation

• What are the levels of organization in multicellular organisms in order of increasing complexity?

  Cells → Tissues → Organs → Organ systems
• What is the basic building block of all living organisms?

  Cell
• What is a tissue?

  A group of cells working together to perform a shared function
• What is an organ?

  A structure made up of groups of different tissues working together
• What is an organ system?

  A group of organs with related functions working together
• What is the description of an organelle?

  • A specialised unit within a cell
  • Performs a specific function
• What is the description of a cell?

  • The basic building block of all living organisms
• What is the description of a tissue?

  • A group of cells working together
  • Performs a shared function
  • Often has a similar structure
• What is the description of an organ?

  • Made up of groups of different tissues
  • Works together to perform specific functions
• What is the description of an organ system?

  • A group of organs with related functions
  • Works together to perform certain functions within the body
• How do the levels of organization in multicellular organisms relate to each other?

  Higher levels are composed of lower levels, e.g., organs are made of tissues.
• Why is the human respiratory system adapted for efficient gas exchange?

  It is designed to maximize the surface area for gas exchange.
• What is the purpose of exchange surfaces in organisms?

  To facilitate the exchange of materials between the organism and its environment.
• What is the significance of the circulatory system in the context of levels of organization?

  It exemplifies how organs and organ systems work together to maintain homeostasis.
• What are the main components of the human gas exchange system?

  • Lungs
  • Alveoli
  • Bronchi
  • Diaphragm
• What are the key functions of the human respiratory system?

  • Gas exchange (oxygen and carbon dioxide)
  • Regulation of blood pH
  • Vocalization