9.3.5 - Adaptations for thermoregulation

Question 1

What are adaptations of organisms that live in colder climates?

Answer 1

Organisms usually larger which reduces SA:V ratio.
Thick layers of fur/blubber
Smaller extremities
Countercurrent exchange systems minimise heat loss to environment.

Question 2

Describe the countercurrent exchange system in organisms that live in cold climates.

Answer 2

Arterial blood is cold as it flows to extremity.
Venous blood is warmed as it returns to the body.
This minimises heat loss to the environment.

Question 3

What are some behavioural adaptations of organisms that live in cold climates?

Answer 3

Eat more food than normal to build up body fat.
Sleep for long periods as metabolism will slow down so energy is saved.

Question 4

What are some adaptations of organisms that live in warmer climates?

Answer 4

Larger extremities (ears) to increase energy transferred to the environment.
Some can tolerate much larger fluctuations in body temperatures.
Countercurrent exchange system helps cool brain.

Question 5

Describe the countercurrent exchange system in organisms that live in warmer climates.

Answer 5

Thermal energy is transferred from arterial blood to venous blood as they run close together. Cooled arterial blood supplied to the brain.

Question 6

What are some behavioural adaptations of organisms that live in warmer climates?

Answer 6

Sheltering - Less radiation absorbed from the sun. They press against cold surfaces to cool by conduction.
Evaporation - Panting allows for the loss of moisture from the mouth.
Aestivation - Organisms slow their metabolic rate down and become completely inactive for months.

Question 7

What is basking?

Answer 7

When an organism absorbs radiation from the sun.