Adaptions for gas exchange

• What does the surface area refer to?

  What does the volume refer to ?

  The total area of the organism that is exposed to the external environment.

  the total internal volume of the organism (total amount of space inside the organism) - the cells
• what happens to the surface area and volume as an organism increase ?


  the surface area : volume ration decreases.

  this is because the volune increases much more rapidly than surface area and size increase
• Define metabolic rate and basal metabolic rate 


  The metabolic rate of an organism is the amount of energy expended by that organism within a given period of time

  • The basal metabolic rate (BMR) is the metabolic rate of an organism when at rest. The BMR is significantly lower than when an organism is actively moving
• how can you measure metabolic rate ?

  Oxygen consumption

  Carbon dioxide production

  Heat production
• what apparatus can you use to investigate metabolic rates ?

  Respirometer

  Oxygen/carbon dioxide probes

  Calorimeters