gas exchange in insects

• What material is the exoskeleton of terrestrial insects made of?

  Chitin
• What is the purpose of the lipid layer in the exoskeleton?

  To prevent water loss
• What type of gas exchange system do terrestrial insects have?

  Tracheal system
• Why is limiting water loss important for terrestrial organisms?

  To balance gas exchange and water retention
• What are the three key adaptations insects have to reduce water loss?

  • Small surface area to volume ratio
  • Lipid layer on exoskeleton
  • Spiracles that can open and close
• What is the function of spiracles in insects?

  To allow gas exchange and water evaporation
• How do spiracles help prevent water loss?

  They can open and close to regulate loss
• What are the three structures within the tracheal system?

  Spiracles, trachea, and tracheoles
• What is the role of trachea in insects?

  To transport gases to tissues
• How do trachea maintain their structure?

  They have rings to prevent collapsing
• What is the function of tracheoles?

  To branch into smaller tubules for gas delivery
• How does simple diffusion occur in insects?

  Due to concentration gradients of gases
• What is mass transport in gas exchange?

  Movement of gases by muscle contractions
• What happens to muscle cells during insect flight?

  They switch from aerobic to anaerobic respiration
• What is produced during anaerobic respiration in insects?

  Lactate or lactic acid
• How does lactate affect water potential in cells?

  It lowers the water potential of the cells
• What causes air to be drawn into the tracheal system?

  A drop in pressure due to volume changes
• What are the key factors for gas exchange in insects?


  • Large surface area from tracheoles
  • Short diffusion distance between spiracles and trachea
  • Maintained concentration gradient by respiration