Module 5: Thermoregulation in ectotherms

Question 1

Define the term thermoregulation

Answer 1

the maintenance of a relatively constant core body temperature to maintain optimum enzyme activity

Question 2

Make 3 initial points about ectotherms

Answer 2

-they use their surroundings to warm their bodies
-their core body temp is heavily dependent on their environment
-they cannot rely on their metabolism to control their temperature

Question 3

Explain why ectotherms living underwater often do not have to thermoregulate

-make 1 point

Answer 3

because the high specific heat capacity of water means the temperature does not change very much

Question 4

Give 3 behavioural responses that ectotherms display in order to thermoregulate
(in this case , to warm up)

Answer 4

-basking in the sun
-orientating their body so that the maximum surface area is exposed to the sun
-extending areas of the body to increase surface area that is exposed to sun

Question 5

Name 2 other ways/processes that ectotherms can increase their body temperature

Answer 5

through CONDUCTION-by pressing their bodies against warm ground/surfaces
through EXOTHERMIC METABOLIC REACTIONS-eg muscle contraction or vibrating

Question 6

Give 5 behavioural responses that ectotherms may use to cool down

Answer 6

-shelter from the sun (dig burrows etc)
-press bodies against cold surfaces
-move into mud/water
-orientate so minimum surface area of body exposed
-minimise movements to reduce metabolic heat generated

Question 7

Give two examples of physiological responses that ectotherms may use to thermoregulate

Answer 7

-alter their heart rate to increase or decrease metabolic rate
-animals living in colder climates adapt to have darker skin as this will absorb more radiation allowing them to warm up