Endotherms and Ectotherms lesson summary

  • Recap of the meanings of homeostasis, negative feedback and positive feedback
  • Sorting of a range of communication pathways into positive and negative feedback: POSIVE - propagation of an action potential, oxytocin release during childbirth; NEGATIVE: temperature control in humans, control of blood water potential in humans
  • Use of video to introduce difference in lifestyle between different organisms:




  • Note that the lizard can move rapidly over short distances but cannot maintain a high level of activity - it mainly relies on AMBUSH PREDATION which is powered largely by anaerobic respiration. Its body temperature varies with the varying temperature of the environment - it is an ECTOTHERM
  • The shrew on the other hand is always ready for large amounts of activity by having a high metabolic rate and a constantly high internal temperature - it is an ENDOTHERM


  • Summary of the benefits and drawbacks of endothermy and ectothermy
  • Summary of the BEHAVIOURAL and PHYSIOLOGICAL adaptations to both lifestyle


MINI TEST NEXT LESSON: Cell membranes and transport across membranes


REMINDER: completed photosynthesis PAG is due by Friday - see previous posts for requirements

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