Ch. 04 pt 2 -Coping with Environmental Variation: Temperature and Water

Animals such as birds and mammals can generate () internally

Heat

Evaporative heat loss in animals includes () in humans, () in dogs and other animals, and () of the body by some marsupials

loss

sweating

panting

Generating heat internally is an ()

advantage

Animals can maintain constant () () near the () for metabolic function under a wide range of external temperatures. These animals can extend their () ()

internal temperatures

optimum

geographic

range

() - regulate body temperature through energy exchange with the external environment

Ectotherms

() - Rely primarily on internal heat generation (mostly birds and mammals), but some fish, insects and plants can generate metabolic

Endotherms

Ectotherms regulate () () through () () with the external environment

body

temperature

energy

exchange

Endotherms rely primarily on () () generation (birds & mammals)

internal heat

Heat exchange with the environment depends on the () () ratio of the body

Surface area-to-volume

as () size (), surface area to-volume ratio (), and large ectotherms are thus improbable

body

increase

decreases

Many () () can move around to adjust temperature

terrestrial ectotherms

Many insects and reptiles bask in the sun to warm up after a cold night. This () risk from (), many are () and can change coloration to match backgrounds

increases

predators

camouflage

Western Fence Lizard basking at the edge of Sun and Shade

() - Range of environmental temperatures over which a constant basal metabolic rate can be maintained

Thermoneutral zone

() -When heat loss is greater than metabolic production; body temperature drops and metabolic heat generation increases

Lower critical temperature

Metabolic rates in endotherms vary with environmental temperatures