Chapter 39

True or False: The increase in red blood cell count in tourists visiting Tibet is an example of acclimatization.

Which of the following examples best describes the concept that form facilitates function? a. Crickets must balance their resources between spermatophore production and immune defenses. b. A desert jackrabbit has large ears that help eliminate excess heat. c. An Antarctic fish maintains homeostasis by conforming to the stable, external temperature. d. Honeybees will swarm around a predatory wasp and contract their flight muscles to generate a lethal ball of heat.

As an animal gets larger, which of the following occurs? a. Its surface area grows more rapidly than its volume. b. Its volume grows more rapidly than its surface area. c. Its volume and surface area increase in perfect proportion to each other. d. Its volume increases, but its total surface area decreases.

Which of the following is an advantage that ectotherms have over endotherms of the same size? a. They require much less food. b. They are less vulnerable to predation during cold weather c. They can remain active in cold weather or on cold nights. d. They have higher metabolic rates and grow more quickly.

For each of the following, explain how structure relates to function: absorptive sections of the digestive tract; capillaries; beaks of Galápagos finches; fish gills.

The metabolic rate of a frog in summer (at \(35^{\circ} \mathrm{C}\) ) is about eight times higher than in winter (at \(5^{\circ} \mathrm{C}\) ). Compare and contrast the frog's ability to move, exchange gases, and digest food at the two temperatures. During which season will the frog require more food energy, and why?

Explain why most endotherms are homeothermic and most ectotherms are poikilothermic.

Consider three spheres with radii of \(1 \mathrm{cm}, 5 \mathrm{cm},\) and \(10 \mathrm{cm} .\) Calculate the surface area and the volume of each sphere, and plot the results on a graph with radius on the \(x\) -axis and surface area and volume on the \(y\) -axis. (Surface area of a sphere \(=4 \pi r^{2}\); volume of a sphere \(=(4 / 3) \pi r^{3}\).) Explain how the graph shows the relationship between size and surface area/volume ratio.

Explain why it would be impossible for a gorilla the size of King Kong to have fur. (Your answer should explain how the surface area/ volume ratio of a normal-sized gorilla would compare to Kong's; relate this to the role of surface area and volume in heat generation and heat transfer; and consider the function of fur.

Suppose that a small mainland tortoise and a large island tortoise are placed in the same pen at a zoo. Which tortoise will be more poikilothermic, the small or large tortoise? Why?

On a trip to the Galápagos Islands, you overhear a group of tourists refer to tortoises as "cold blooded." Explain why this word is not accurate to describe a giant tortoise.