10A: Adaptations to arid environments

Question 1

What are structural adaptations for arid environments?

Answer 1

• Insulation (top of camel has thick fur to prevent heat absorption from sun, but underside has thin insulation, that releases large amounts of heat)
• High SA:V ratio to release large amounts of heat

Question 2

What are physiological adaptations for arid environments?

Answer 2

• Metabolic heat (more ectotherms)
• Vasodilation
• Increased water input (drinking dewfall)
• Increase water reabsorption (loop of Henle)

Question 3

What are behavioral adaptations for arid environments?

Answer 3

• Evading extreme conditions (avoid in shade, burrow)
• Enduring extreme conditions (inactivity during hottest times - dig pits in sand to release heat into cool soil)
• Nocturnal behaviour

Question 4

Challenges of hot environments?

Answer 4

• Temperature
• Humidity (hard to cool down)
• Radiation (UV causes cellular damage)
• Water availability

Question 5

An animal with a high SA:V ratio…

Answer 5

Releases or absorbs a large amount of heat in little time, allowing quick change of body temp.

Question 6

An animal with a low SA:V ratio…

Answer 6

Releases or absorbs low amounts of heat, and internal body temp is resistant to change

Question 7

What is an endotherm?

Answer 7

Animal that produces the majority of its own heat via metabolic processes (mammals, birds)

Question 8

What is an ectotherm?

Answer 8

An animal that obtains heat primarily from the environment, rather than its own metabolic heat (amphibians, reptiles)

Question 9

What are sources of water in arid environments?

Answer 9

Drinking dewfall
Production of water during aerobic cellular respiration
Eating plants/insects