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QUIZ: DESERT ADAPTATION
Sources: PowerPoint 02d
1. Too hot and proteins break down. Too cold and body functions don't work as well.
2. Every 10 degrees C rise in temperature results in a doubling of the rate of biochemical reactions (metabolism), up to a point. It is important because how quickly an organism functions (digests, moves, thinks, etc.) depends on its rate of metabolism which depends on its body temperature. Also higher rates of metabolism require more energy and water.
3. Radiation: heat gain/loss because essentially all objects give off heat
so every object is losing heat from itself and gaining heat from other objects
(e.g., the sun, a rock, etc.).
Convection: heat gain/loss by moving air (wind) or water.
Conduction: heat gain/loss between touching objects.
Metabolism: heat gain due to biochemical reactions produced in the body (e.g., muscle contraction).
Evaporation: heat loss due to the conversion of water from liquid to gas.
4. Ectotherms: principal source of body heat is from the environment. All
but mammals and birds.
Endotherms: principal source of body heat is internally, from metabolism. Mammals and birds.
5. Using posture, orientation, and microclimate selection (e.g., burrow) to regulate body temperature.
6. Altering metabolic generation of body heat to regulate body temperature.
7. Ectothermy: Advantage: uses 10X less energy.
Disadvantage: must be cold and slow when lack environmental source of heat.
Endothermy: Advantage: always ready to go (don't have to depend on environment for heat).
Disadvantage: uses 10X more energy.
8. Less insulation = faster rate
Higher Temperature difference between body and environment (temperature gradient) = faster rate
Higher Surface area to volume ratio = faster rate
9. Mouse. So the mouse loses heat faster so must eat more food per pound of body weight.
10. A lowering of the body temperature below activity temperature.
11. Types of torpor:
i. Daily torpor in response to cold: daily torpor in response to cold
ii. Hibernation: seasonal torpor in response to cold
iii. Daily estivation: daily torpor in response to heat/dryness
iv. Seasonal estivation: seasonal torpor in response to heat/dryness
12. Torpor Adaptive Values
13. Endure, Evade, Expire
14. Outline for Enduring
15. Water Storage: succulence, fat storage
Spatial: migration, microclimate selection
Temporal: nocturnal, torpor
16. Uric acid uses 10X less water, but costs additional energy. Birds, snakes, lizards, some insects do this.