Insects

• What is the purpose of the exoskeleton in terrestrial insects?

  To protect and prevent water loss
• What material is the exoskeleton of terrestrial insects made of?

  Chitin
• Why do terrestrial insects not have lungs?

  They have a tracheal system for gas exchange
• What is a major challenge for terrestrial organisms regarding gas exchange?

  Balancing gas exchange with water loss
• 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?

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

  They can open and close to regulate gas exchange
• What is the main component of the exoskeleton of terrestrial insects?

  Chitin
• Why do terrestrial insects have a lipid layer in their exoskeleton?

  To prevent water loss
• What is the gas exchange system used by terrestrial insects instead of lungs?

  Tracheal system
• How do the spiracles in the tracheal system of terrestrial insects help reduce water loss?

  They can open and close to control water evaporation
• What are the three main structures in the tracheal system of terrestrial insects?

  Spiracles, trachea, and tracheoles
• How do the tracheal tubes in terrestrial insects stay open?

  They have rings within them to prevent collapse
• How do the muscles in the abdomen of terrestrial insects help with gas exchange?

  They can contract and relax to pump gases in and out
• How does the tracheal system in terrestrial insects differ from the respiratory system in vertebrates?

  Insects have a tracheal system with spiracles, while vertebrates have lungs
• What are the key adaptations of terrestrial insects to reduce water loss?

  • Small surface area to volume ratio of the tracheal system
  • Lipid layer on the exoskeleton to be waterproof
  • Ability to open and close spiracles to control water evaporation
• How does gas exchange occur in the tracheal system of terrestrial insects?

  • Diffusion of gases down concentration gradients
  • Muscle contractions in the abdomen to pump gases in and out
  • Fluid pressure changes due to anaerobic respiration and lactic acid production
• What is the formula to calculate the area of a circle?

  $A =$$\pi r^2$