(Unit 2.3) Metabolic Rate

• What are the three main ways to measure metabolic rate?

  Oxygen consumption, carbon dioxide production, and heat produced
• What device is used to measure oxygen consumption?

  Respirometer
• How does a respirometer work?

  It measures the rise of liquid as an organism consumes oxygen
• What is the purpose of using a control in a respirometer experiment?

  To ensure that the organism is the one consuming oxygen
• What is the main principle of a respirometer?

  Measuring the volume of oxygen used per unit of time
• What are the classifications of organisms based on metabolic rates?

  • Birds and mammals: higher metabolic rates
  • Reptiles, amphibians, and fish: lower metabolic rates
  • Variations exist within these classifications
• Why do birds and mammals require a more efficient circulatory system?

  To deliver oxygen efficiently to their cells
• What are the components of the circulatory system?

  • Heart
  • Blood
  • Blood vessels
• What is the structure of the heart in birds and mammals?

  It has two atria and two ventricles separated by a septum
• How does blood flow through the heart in birds and mammals?

  Deoxygenated blood enters the right atrium, goes to the right ventricle, and is sent to the lungs
• What is the significance of the complete double circulatory system?

  It prevents mixing of oxygenated and deoxygenated blood
• What is the circulatory system of amphibians and reptiles called?

  Incomplete double circulatory system
• How does the incomplete double circulatory system affect metabolic rate?

  It mixes oxygenated and deoxygenated blood, reducing efficiency
• What is the circulatory system of fish called?

  Single circulatory system
• How does blood flow in the single circulatory system of fish?

  Blood passes through the heart once in each complete circuit
• What happens to blood pressure as it passes through the gills in fish?

  There is a big drop in pressure
• What is the main takeaway regarding metabolic rates and oxygen delivery?

  High metabolic rates require effective and efficient oxygen delivery
• What are the key points to remember about measuring metabolic rate?

  • Methods include oxygen consumption, carbon dioxide production, and heat produced
  • Respirometers measure oxygen consumption
  • Controls are necessary to ensure accurate measurements
• What are the differences between the circulatory systems of birds, mammals, amphibians, reptiles, and fish?

  • Birds and mammals: complete double circulatory system
  • Amphibians and reptiles: incomplete double circulatory system
  • Fish: single circulatory system