Homeostasis - Thermoregulation in ectotherms and endotherms

Question 1

Physical processes in response to organisms heating / cooling in environment?

Answer 1

• Exothermic chemical reactions
• Latent heat of evaporation - objects cool down as water evaporates from a surface
• Radiation - transmission of electromagnetic waves to and from the air, water or ground
• Convection - heating and cooling by currents of air / water
• Conduction - heating as a result of collision of molecules. Air is not a good conductor of heat but ground and water are

Question 2

Ectotherms:

Answer 2

Can not generate their own heat and therefore alter their behaviour and physiology in order to exchange heat with their environment

Question 3

Endotherms

Answer 3

Can generate their own heat by altering their rate of metabolism. They alter their physiology and behaviour too.

Question 4

Ectotherms examples:

Answer 4

• invertebrate animals
• fish
• amphibians
• reptiles

Question 5

Thermoregulation in ectotherms:

Answer 5

• Do not need to thermoregulate
• In water - the high heat capacity of water means that the temperature of their environment is constant
• Land - temperature of air changes with seasons

Question 6

Endotherm examples:

Answer 6

• Mammals
• Birds

Question 7

Metabolic rate of endotherms:

Answer 7

Higher than ectotherms, so need to consume more food to meet their metabolic needs.