38. Animal Form and Function

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

What are three attributes of mitochondria and chloroplasts that suggest they were once free-living bacteria?

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.

Consider the energy budgets for a human, an elephant, a penguin, a mouse, and a snake. The          would have the highest total annual energy expenditure, and the          would have the highest energy expenditure per unit mass. a. elephant; mouse b. elephant; human c. mouse; snake d. penguin; mouse

The cells of an ant and an elephant are, on average, the same small size; an elephant just has more of them. What is the main advantage of small cell size? (Explain your reasoning.) a. A small cell has a larger plasma membrane surface area than does a large cell. b. Small cells can better take up sufficient nutrients and oxygen to service their cell volume. c. It takes less energy to make an organism out of small cells. d. Small cells require less oxygen than do large cells.

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.

Compared with a smaller cell, a larger cell of the same shape has a. less surface area. b. less surface area per unit of volume. c. the same surface-area-to-volume ratio. d. a smaller cytoplasm-to-nucleus ratio.

An animal's inputs of energy and materials would exceed its outputs a. if the animal is an endotherm, which must always take in more energy because of its high metabolic rate. b. if it is actively foraging for food. c. if it is growing and increasing its mass. d. never; due to homeostasis, these energy and material budgets always balance.

Which of the following cell structures would you expect to be most important in the growth of bacteria on the surface of your teeth? a. cell wall b. fimbriae c. flagella d. cilia

Which of the following animals uses the largest percentage of its energy budget for homeostatic regulation? a. marine jelly (an invertebrate) b. snake in a temperate forest c. desert insect d. desert bird

______ refers to the protection of the internal environment against the harms of changes in the external environment. 

DRAW IT Draw a model of the control circuit(s) required for driving an automobile at a fairly constant speed over a hilly road. Indicate each feature that represents a sensor, stimulus, or response.

The eukaryotic cytoskeleton is a highly dynamic network of filaments and motor proteins. Which of the following correctly describe activities of these cytoskeletal components? Select True or False for each statement. T/F Myosin motors walk toward the plus ends of intermediate filaments. T/F Dynein motors are responsible for the whip-like movement of eukaryotic flagella. T/F Kinesin motors move vesicles along tracks toward the microtubule-organizing center. T/F Actin filaments are required for cytoplasmic streaming.

Suppose a cell is placed in a solution with a high concentration of potassium and no sodium. How would the cellular sodium–potassium pump function in this environment? a. It would stop moving ions across the membrane. b. It would continue using ATP to pump sodium out of the cell and potassium into the cell. c. It would move sodium and potassium ions across the membrane, but no ATP would be used. d. It would reverse the direction of sodium and potassium ions to move them against their gradients.

George Palade's research group used the pulse–chase assay to elucidate the secretory pathway in pancreatic cells. If they had instead performed this assay on muscle cells, where would you expect the labeled proteins to end up during the chase? (Muscle cells consist primarily of actin and myosin filaments and have high energy demands for muscle contraction.)

Examine the experimental chamber in Figure 6.8a. Explain what would occur by osmosis if you added a 1-M solution of sodium chloride on the left side and an equal volume of a 1.5 M solution of potassium ions on the right. How might the addition of the CFTR protein to the lipid bilayer impact the direction of water movement?

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 allows species to exploit more resources and frees 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 allows species to exploit more resources and frees 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 allows species to exploit more resources and frees 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 allows species to exploit more resources and frees 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 allows species to exploit more resources and frees 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 allows species to exploit more resources and frees 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.