1 Chapter 7 Animal adaptations to the Environments

2 Challenges of terrestrial animals Temperature Moisture

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4 Surface area-volume ratio

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6 Adaptation to temperature

7 Adaptations to temperatures

8 Body Temperature Regulation Ectotherms –Rely mainly on external energy sources. Endotherms –Rely heavily on metabolic energy. Poikilotherms –Body temperature varies directly with environmental temperature. Homeotherms –maintain a relatively constant internal environment

9 Temperature Regulation by Ectothermic Animals

10 Behavioral thermoregulation

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12 Acclimatization: long-term temperature regulation

13 Temperature Regulation by Endothermic Animals Thermal neutral zone is the range of environmental temperatures over which the metabolic rate of a homeothermic animal does not change. –Breadth varies among endothermic species.

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18 Countercurrent heat exchange

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22 Surviving Extreme Temperatures Inactivity –Seek shelter during extreme periods. Reducing Metabolic Rate Hummingbirds enter a state of torpor when food is scarce and night temps are extreme. Hibernation - Winter Estivation – Summer Migration

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26 Adaptation to water

27 (II) Water Regulation on Land Terrestrial organisms face (2) major challenges: –Evaporative loss to environment. –Reduced access to replacement water.

28 Water Regulation on Land W ia = W d + W f + W a - W e - W s W ia = Animal’s internal water W d = Drinking W f = Food W a = Absorbed by air W e = Evaporation W s = Secretion / Excretion

29 Water Regulation on Land

30 Water Acquisition Most terrestrial animals satisfy their water needs via eating and drinking. –Can also be gained via metabolism through oxidation of glucose: C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O –Metabolic water refers to the water released during cellular respiration.

31 Water regulation of terrestrial animals

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35 (III) Water Movement in Aquatic Environments If two environments differ in water or salt concentrations, substances will tend to move down their concentration gradients. –Diffusion Osmosis: Diffusion through a semipermeable membrane.

36 (III) Water Movement in Aquatic Environment Isomotic: Body fluids and external fluid are at the same concentration. Hypoosmotic: Body fluids are at a higher concentration than the external environment. Hyperosmotic: Body fluids are at a lower concentration than the external environment.

37 loss Gain loss

38 (IV) Water and Salt Balance Water regulation of hyperosmotic animals

39 Hypoosmotic animals

40 Mitochondria-rich cell

41 上課完畢，謝謝 !