Chapter 40 Flashcards
1
Q
Importance of Temperature (3)
A
- Temperature influences species distribution
- Temperature impacts biochemical reaction rates
- All organisms have an optimal temperature range
2
Q
Temperature Regulation (4 Parts)
A
- Regulation
- Body Temperature
- Heat Source
- Living is Energetically Expensive
3
Q
Regulation (2)
A
- Regulator: different temperature from environment
2. Conformer: same temperature as environment
4
Q
Body Temperature (2)
A
- Homeothermic: constant temperature
2. Poikilothermic: variable body temperature
5
Q
Heat Source (2)
A
- Endothermic: primarily from metabolism
2. Ectothermic: primarily from environment
6
Q
Living is Energetically Expensive
A
Worse for small endotherms especially
7
Q
Heat Exchange
A
- high to low temperature
- determines body temperature in ectotherms (endoderms use metabolism to counteract)
- 4 mechanisms
8
Q
Thermal Regulation: Controlling Heat Exchange (2)
A
- Radiation: emission of electromagnetic waves by all objects warmer than absolute zero
- Physical and behavioral adaptations alter radiative exchange
9
Q
Evaporation (3)
A
- It takes energy to evaporate water, so organisms lose heat with water
- Terrestrial Animals: skin and respiratory tissues
- Plants: transpiration
10
Q
Conduction
A
Direct transfer of heat between molecules of objects in contact
11
Q
Convection (3)
A
- Transfer of heat by the movement of air or liquid past a surface
- Integument (hair, feathers) traps air and increases boundary layer reducing convection (and reduces evaporation)
- Internal insulation (fat, blubber) reduces conduction and convection
12
Q
Thermal Homeostasis (4)
A
- Thermal regulators aim for thermal homeostasis
- In mammals thermostat is the hypothalamus
- ‘Normal Range’ rather than absolute set-point
- Some plants control flower temperature
