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

Which of these 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.

Which of the following statements regarding surface area and volume in animals are correct? Select True or False for each statement.

T/F As an animal grows, its volume increases more rapidly than its surface area.

T/F A chihuahua has a higher surface area to volume ratio than a Great Dane.

T/F Animals with high surface area to volume ratios heat and cool more slowly than animals with lower surface area to volume ratios.

T/F As an animal's volume increases, 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°C) is about eight times higher than in winter (at 5°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.

a. Consider three spheres with radii of 1 cm, 5 cm, and 10 cm. Based on what you read in the chapter, predict which sphere will have the highest surface area to volume ratio, and which sphere will have the lowest.

b. Next, calculate the surface area and the volume of each sphere. (Surface area of a sphere=4𝜋𝑟2; volume of a sphere=(4/3)𝜋𝑟3.) Plot the results on a graph with radius on the 𝑥-axis and surface area and volume on the 𝑦-axis.

c. Which sphere has the highest surface area to volume ratio? The lowest? Explain how the graph shows the relationship between size and surface area to volume ratio.

d. Now imagine that these spheres represent a small, medium, and large endothermic animal. Which animal would lose heat most rapidly? Explain using the surface area to volume ratio.

Consider three spheres with radii of 1 cm, 5 cm, and 10 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 = 4πr2; volume of a sphere = (4/3)πr3.)

Explain how the graph shows the relationship between size and surface area to 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 to 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.)

The dinosaur Apatosaurus (Brontosaurus) is one of the largest terrestrial animals that ever lived—over 20 m in length and weighing over 20 metric tons. Is it more likely that Apatosaurus was homeothermic or poikilothermic? Explain.

Many species of animals on islands are larger than related species on the mainland. Scientists hypothesize that this phenomenon, called island gigantism, evolved in response to the scarcity of competitors and predators on islands. Reduced competition and predation allow species to exploit more resources and free them from the need to hide in small refuges. The graph shown here compares the average carapace (shell) length of mainland and island tortoises. Summarize the results, then use the data to predict whether the surface area to volume ratio is higher in mainland or island tortoises.

Many species of animals on islands are larger than related species on the mainland. Scientists hypothesize that this phenomenon, called island gigantism, evolved in response to the scarcity of competitors and predators on islands. Reduced competition and predation allow species to exploit more resources and free them from the need to hide in small refuges.

Which tortoises, mainland or island, need to eat more food per gram of their body mass?

Many species of animals on islands are larger than related species on the mainland. Scientists hypothesize that this phenomenon, called island gigantism, evolved in response to the scarcity of competitors and predators on islands. Reduced competition and predation allow species to exploit more resources and free them from the need to hide in small refuges. Which of the following might be a trade-off of gigantism experienced by giant island tortoises?

a. They cool very rapidly during cold weather.

b. It would be difficult to sustain their high mass-specific metabolic rates on a diet of plants alone.

c. It could be more difficult to avoid thermally unfavorable conditions.

d. They could hide from nonnative predators more easily.

Many species of animals on islands are larger than related species on the mainland. Scientists hypothesize that this phenomenon, called island gigantism, evolved in response to the scarcity of competitors and predators on islands. Reduced competition and predation allow species to exploit more resources and free them from the need to hide in small refuges.

True or false: The body temperatures of island tortoises always closely match the temperatures in their environments.

Many species of animals on islands are larger than related species on the mainland. Scientists hypothesize that this phenomenon, called island gigantism, evolved in response to the scarcity of competitors and predators on islands. Reduced competition and predation allow species to exploit more resources and free them from the need to hide in small refuges. 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?

Many species of animals on islands are larger than related species on the mainland. Scientists hypothesize that this phenomenon, called island gigantism, evolved in response to the scarcity of competitors and predators on islands. Reduced competition and predation allow species to exploit more resources and free them from the need to hide in small refuges. 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.