Unit 2.4 - Conformers and Regulators

• What affects an organisms metabolic rate due to its external environment?

  Abiotic factors
• What are examples of abiotic factors?

  Temperature, salinity and pH
• What do conformers do?

  Adapt and conform to the external environment
• What do regulators do?

  Maintain their metabolic state themselves.
• Describe conformers behavioral response.

  Behavioral responses allows them to tolerate variation in their external environment to maintain optimum metabolic rate.
• Explain a conformers response to changes in the external environment

  Internal environment changes in response to changes in external environment.
• Explain a regulators response to changes in the external environment

  Internal environment remains constantly physiologically adapts to changes in external environment.
• Is a conformers metabolic cost low or high?

  Low
• Is a regulators metabolic cost low or high?

  High
• What is a conformers ecological niche like?

  Narrow
• What is a regulators ecological niche like?

  Wide
• How is optimum metabolic rate obtained in conformers?

  Behavioral responses
• How is optimum metabolic rate obtained in regulators?

  Physiological mechanisms
• What is homeostasis?

  Maintenance of the body's internal environment within limits despite the external environment.
• Explain regulation

  Requires energy and is under negative feedback control.
• What is negative feedback control?

  When a body's internal environment deviates from 'normal', it is detected by receptors. Receptors send hormonal or nervous impulses. Effectors act to return the internal environment back to 'normal'.
• What is thermoregulation?


  The use of negative feedback in regulation of body temperature in mammals.
• What does the hypothalamus do?

  Contains thermoreceptors and receives impulses from receptors in the skin. Also senses the temperature of blood. Sends appropriate impulses to effectors to trigger corrective feedback.
• What happens when the body temperature decreases?

  1. Shivering - muscles generate heat

  2. Vasoconstriction - decreased blood flow to skin decreases heat loss
  3. Hair erector muscles contract - traps layers of insulting air
  4. Increased metabolic rates - more heat produced.
• What happens when the body temperature increases?

  1. Sweating - body heat used to evaporate water in the sweat, cooling the skin.
  2. Vasodilation - increased blood flow to the skin increases heat loss by radiation
  3. Decreased metabolic rate - less heat produced
  4. Hair erector muscles relax
• What are the advantages of maintaining a constant body temperature?

  Maintains a high metabolic rate if the animal can keep optimum temperature for enzyme activity. Temperature can also affect rates of diffusion. Oxygen and carbon dioxide diffuse quicker at a higher temperature, high rates of diffusion of these gases maintains high metabolic activity.