Animal Form and Function Quiz

PDF page 1027: As you have learned, specialized cells in the animal body are organized into tissues, organs, and organ systems, which efficiently localize functions, such as the digestion of food and the elimination of wastes. As we explore the information in this section, our primary focus is homeostasis—the ability to maintain dynamic equilibrium around a set point. Animals need to maintain their “normal” internal environments while also responding to external environmental changes. In our study of biology thus far, we have seen numerous examples of structure-function relationships, and the design of the animal body is no exception. Specialization in multicellular animals contributes to efficiency in cell processes. For example, animals must be able to procure nutrients and eliminate wastes, and cells that line the small intestine allow for diffusion. Furthermore, the relationship between metabolic rate and body mass is typically an inverse one: The smaller the animal, the higher its metabolism, with mice having a higher metabolic rate than, for example, elephants. Because mice have a greater surface area-to-volume ratio for their mass than larger animals, they lose heat at a faster rate and, consequently, require more energy to maintain constant body temperature. Speaking of temperature, we learned that the body temperature of ectothermic animals varies according to environmental temperatures. When snakes need to warm up, they bask in the sun; when they need to cool down, they go into the shade. Other animals, including mice, kangaroos and humans, are endothermic because they are able to maintain a fairly constant internal body temperature despite environmental temperatures; for example, shivering generates heat, whereas sweating returns our body temperature to its normal set point of 37◦C. We will explore the control of these responses in more detail in the Homeostasis section.

PDF page 1027: As you have learned, specialized cells in the animal body are organized into tissues, organs, and organ systems, which efficiently localize functions, such as the digestion of food and the elimination of wastes. As we explore the information in this section, our primary focus is homeostasis—the ability to maintain dynamic equilibrium around a set point. Animals need to maintain their “normal” internal environments while also responding to external environmental changes. In our study of biology thus far, we have seen numerous examples of structure-function relationships, and the design of the animal body is no exception. Specialization in multicellular animals contributes to efficiency in cell processes. For example, animals must be able to procure nutrients and eliminate wastes, and cells that line the small intestine allow for diffusion. Furthermore, the relationship between metabolic rate and body mass is typically an inverse one: The smaller the animal, the higher its metabolism, with mice having a higher metabolic rate than, for example, elephants. Because mice have a greater surface area-to-volume ratio for their mass than larger animals, they lose heat at a faster rate and, consequently, require more energy to maintain constant body temperature. Speaking of temperature, we learned that the body temperature of ectothermic animals varies according to environmental temperatures. When snakes need to warm up, they bask in the sun; when they need to cool down, they go into the shade. Other animals, including mice, kangaroos and humans, are endothermic because they are able to maintain a fairly constant internal body temperature despite environmental temperatures; for example, shivering generates heat, whereas sweating returns our body temperature to its normal set point of 37◦C. We will explore the control of these responses in more detail in the Homeostasis section.

PDF page 1027: As you have learned, specialized cells in the animal body are organized into tissues, organs, and organ systems, which efficiently localize functions, such as the digestion of food and the elimination of wastes. As we explore the information in this section, our primary focus is homeostasis—the ability to maintain dynamic equilibrium around a set point. Animals need to maintain their “normal” internal environments while also responding to external environmental changes. In our study of biology thus far, we have seen numerous examples of structure-function relationships, and the design of the animal body is no exception. Specialization in multicellular animals contributes to efficiency in cell processes. For example, animals must be able to procure nutrients and eliminate wastes, and cells that line the small intestine allow for diffusion. Furthermore, the relationship between metabolic rate and body mass is typically an inverse one: The smaller the animal, the higher its metabolism, with mice having a higher metabolic rate than, for example, elephants. Because mice have a greater surface area-to-volume ratio for their mass than larger animals, they lose heat at a faster rate and, consequently, require more energy to maintain constant body temperature. Speaking of temperature, we learned that the body temperature of ectothermic animals varies according to environmental temperatures. When snakes need to warm up, they bask in the sun; when they need to cool down, they go into the shade. Other animals, including mice, kangaroos and humans, are endothermic because they are able to maintain a fairly constant internal body temperature despite environmental temperatures; for example, shivering generates heat, whereas sweating returns our body temperature to its normal set point of 37◦C. We will explore the control of these responses in more detail in the Homeostasis section.

PDF page 1032: Figure 24.4 The mouse has a much higher metabolic rate than the elephant. (credit “mouse”: modification of work by

PDF page 1027: As you have learned, specialized cells in the animal body are organized into tissues, organs, and organ systems, which efficiently localize functions, such as the digestion of food and the elimination of wastes. As we explore the information in this section, our primary focus is homeostasis—the ability to maintain dynamic equilibrium around a set point. Animals need to maintain their “normal” internal environments while also responding to external environmental changes. In our study of biology thus far, we have seen numerous examples of structure-function relationships, and the design of the animal body is no exception. Specialization in multicellular animals contributes to efficiency in cell processes. For example, animals must be able to procure nutrients and eliminate wastes, and cells that line the small intestine allow for diffusion. Furthermore, the relationship between metabolic rate and body mass is typically an inverse one: The smaller the animal, the higher its metabolism, with mice having a higher metabolic rate than, for example, elephants. Because mice have a greater surface area-to-volume ratio for their mass than larger animals, they lose heat at a faster rate and, consequently, require more energy to maintain constant body temperature. Speaking of temperature, we learned that the body temperature of ectothermic animals varies according to environmental temperatures. When snakes need to warm up, they bask in the sun; when they need to cool down, they go into the shade. Other animals, including mice, kangaroos and humans, are endothermic because they are able to maintain a fairly constant internal body temperature despite environmental temperatures; for example, shivering generates heat, whereas sweating returns our body temperature to its normal set point of 37◦C. We will explore the control of these responses in more detail in the Homeostasis section.

PDF page 1031: All animals must obtain their energy from food they ingest or absorb. These nutrients are converted to adenosine triphosphate (ATP) for short-term storage and use by all cells. Some animals store energy for slightly longer times as glycogen, and others store energy for much longer times in the form of triglycerides housed in specialized adipose tissues. No energy system is one hundred percent efficient, and an animal’s metabolism produces waste energy in the form of heat. If an animal can conserve that heat and maintain a relatively constant body temperature, it is classified as a warm-blooded animal and called an endotherm. The insulation used to conserve the body heat comes in the forms of fur, fat, or feathers. The absence of insulation in ectothermic animals increases their dependence on the environment for body heat. The amount of energy expended by an animal over a specific time is called its metabolic rate. The rate is measured variously in joules, calories, or kilocalories (1000 calories). Carbohydrates and proteins contain about 4.5 to 5 kcal/g, and fat contains about 9 kcal/g. Metabolic rate is estimated as the basal metabolic rate (BMR) in endothermic animals at rest and as the standard metabolic rate (SMR) in ectotherms. Human males have a BMR of 1600 to 1800 kcal/day, and human females have a BMR of 1300 to 1500 kcal/day. Even with insulation, endothermal animals require extensive amounts of energy to maintain a constant body temperature. An ectotherm such as an alligator has an SMR of 60 kcal/day. Energy Requirements Related to Body Size Smaller endothermic animals have a greater surface area for their mass than larger ones (Figure 24.4). Therefore, smaller animals lose heat at a faster rate than larger animals and require more energy to maintain a constant internal temperature. This results in a smaller endothermic animal having a higher BMR, per body weight, than a larger endothermic animal.

PDF page 1027: As you have learned, specialized cells in the animal body are organized into tissues, organs, and organ systems, which efficiently localize functions, such as the digestion of food and the elimination of wastes. As we explore the information in this section, our primary focus is homeostasis—the ability to maintain dynamic equilibrium around a set point. Animals need to maintain their “normal” internal environments while also responding to external environmental changes. In our study of biology thus far, we have seen numerous examples of structure-function relationships, and the design of the animal body is no exception. Specialization in multicellular animals contributes to efficiency in cell processes. For example, animals must be able to procure nutrients and eliminate wastes, and cells that line the small intestine allow for diffusion. Furthermore, the relationship between metabolic rate and body mass is typically an inverse one: The smaller the animal, the higher its metabolism, with mice having a higher metabolic rate than, for example, elephants. Because mice have a greater surface area-to-volume ratio for their mass than larger animals, they lose heat at a faster rate and, consequently, require more energy to maintain constant body temperature. Speaking of temperature, we learned that the body temperature of ectothermic animals varies according to environmental temperatures. When snakes need to warm up, they bask in the sun; when they need to cool down, they go into the shade. Other animals, including mice, kangaroos and humans, are endothermic because they are able to maintain a fairly constant internal body temperature despite environmental temperatures; for example, shivering generates heat, whereas sweating returns our body temperature to its normal set point of 37◦C. We will explore the control of these responses in more detail in the Homeostasis section.

PDF page 1027: As you have learned, specialized cells in the animal body are organized into tissues, organs, and organ systems, which efficiently localize functions, such as the digestion of food and the elimination of wastes. As we explore the information in this section, our primary focus is homeostasis—the ability to maintain dynamic equilibrium around a set point. Animals need to maintain their “normal” internal environments while also responding to external environmental changes. In our study of biology thus far, we have seen numerous examples of structure-function relationships, and the design of the animal body is no exception. Specialization in multicellular animals contributes to efficiency in cell processes. For example, animals must be able to procure nutrients and eliminate wastes, and cells that line the small intestine allow for diffusion. Furthermore, the relationship between metabolic rate and body mass is typically an inverse one: The smaller the animal, the higher its metabolism, with mice having a higher metabolic rate than, for example, elephants. Because mice have a greater surface area-to-volume ratio for their mass than larger animals, they lose heat at a faster rate and, consequently, require more energy to maintain constant body temperature. Speaking of temperature, we learned that the body temperature of ectothermic animals varies according to environmental temperatures. When snakes need to warm up, they bask in the sun; when they need to cool down, they go into the shade. Other animals, including mice, kangaroos and humans, are endothermic because they are able to maintain a fairly constant internal body temperature despite environmental temperatures; for example, shivering generates heat, whereas sweating returns our body temperature to its normal set point of 37◦C. We will explore the control of these responses in more detail in the Homeostasis section.

PDF page 1028: Figure 24.2 Animals exhibit different types of body symmetry. The sponge is asymmetrical, the sea anemone has

PDF page 1028: Animal body plans follow set patterns related to symmetry. They are asymmetrical, radial, or bilateral in form as illustrated in Figure 24.2. Asymmetrical animals are animals with no pattern or symmetry; an example of an asymmetrical animal is a sponge. Radial symmetry, as illustrated in Figure 24.2, describes when an animal has an up-and-down orientation: any plane cut along its longitudinal axis through the organism produces equal halves, but not a definite right or left side. This plan is found mostly in aquatic animals, especially organisms that attach themselves to a base, like a rock or a boat, and extract their food from the surrounding water as it flows around the organism. Bilateral symmetry is illustrated in the same

PDF page 1028: Animal body plans follow set patterns related to symmetry. They are asymmetrical, radial, or bilateral in form as illustrated in Figure 24.2. Asymmetrical animals are animals with no pattern or symmetry; an example of an asymmetrical animal is a sponge. Radial symmetry, as illustrated in Figure 24.2, describes when an animal has an up-and-down orientation: any plane cut along its longitudinal axis through the organism produces equal halves, but not a definite right or left side. This plan is found mostly in aquatic animals, especially organisms that attach themselves to a base, like a rock or a boat, and extract their food from the surrounding water as it flows around the organism. Bilateral symmetry is illustrated in the same

PDF page 1029: animal into definite right and left sides. Additional terms used when describing positions in the body are anterior (front), posterior (rear), dorsal (toward the back), and ventral (toward the stomach). Bilateral symmetry is found in both land-based and aquatic animals; it enables a high level of mobility.

PDF page 1029: animal into definite right and left sides. Additional terms used when describing positions in the body are anterior (front), posterior (rear), dorsal (toward the back), and ventral (toward the stomach). Bilateral symmetry is found in both land-based and aquatic animals; it enables a high level of mobility.

PDF page 1029: Animals with bilateral symmetry that live in water tend to have a fusiform shape: this is a tubular shaped body that is tapered at both ends. This shape decreases the drag on the body as it moves through water and allows the animal to swim at high speeds. Table 24.1 lists the maximum speed of various animals. Certain types of sharks can swim at fifty kilometers an hour and some dolphins at 32 to 40 kilometers per hour. Land animals frequently travel faster, although the tortoise and snail are significantly slower than cheetahs. Another difference in the adaptations of aquatic and land-dwelling organisms is that aquatic organisms are constrained in shape by the forces of drag in the water since water has higher viscosity than air. On the other hand, land-dwelling organisms are constrained mainly by gravity, and drag is relatively unimportant. For example, most adaptations in birds are for gravity not for drag.

PDF page 1029: Animal Speed (kmh) Speed (mph) Cheetah 113 70 Quarter horse 77 48 Fox 68 42 Shortfin mako shark 50 31 Domestic house cat 48 30 Human 45 28 Dolphin 32–40 20–25 Mouse 13 8 Snail 0.05 0.03