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Figure 40.1 CAMPBELL BIOLOGY Figure 40.1a Diverse Forms, Common Challenges TENTH EDITION Reece • Urry • Cain • Wasserman • Minorsky • Jackson ! Anatomy is the biological form of an organism 40 ! Physiology is the biological functions an organism performs ! The comparative study of animals reveals that form and function are closely correlated Basic Principles of Animal Form and Function Lecture Presentation by Nicole Tunbridge and Kathleen Fitzpatrick 2 © 2014 Pearson Education, Inc. © 2014 Pearson Education, Inc. Concept 40.1: Animal form and function are correlated at all levels of organization Evolution of Animal Size and Shape 3 © 2014 Pearson Education, Inc. Figure 40.2 ! Size and shape affect the way an animal interacts with its environment ! Physical laws govern strength, diffusion, movement, and heat exchange ! The body plan of an animal is programmed by the genome, itself the product of millions of years of evolution ! Properties of water limit possible shapes for fast swimming animals Penguin ! Convergent evolution often results in similar adaptations of diverse organisms facing the same challenge © 2014 Pearson Education, Inc. Tuna 6 © 2014 Pearson Education, Inc. Figure 40.2b Figure 40.2a Seal ! As animals increase in size, thicker skeletons are required for support 5 4 © 2014 Pearson Education, Inc. 7 © 2014 Pearson Education, Inc. 8 Seal © 2014 Pearson Education, Inc. Figure 40.2c Exchange with the Environment Penguin 9 © 2014 Pearson Education, Inc. Tuna ! Materials such as nutrients, waste products, and gases must be exchanged across the cell membranes of animal cells ! A single-celled organism living in water has sufficient surface area to carry out all necessary exchange ! Rate of exchange is proportional to a cell’s surface area while amount of exchange material is proportional to a cell’s volume ! Multicellular organisms with a saclike body plan have body walls that are only two cells thick, facilitating diffusion of materials 10 © 2014 Pearson Education, Inc. 11 © 2014 Pearson Education, Inc. Figure 40.3 Figure 40.4 Video: Hydra Eating Daphnia External environment Exchange Exchange 0.1 mm (a) An amoeba, a single-celled organism Heart 15 © 2014 Pearson Education, Inc. Cells Circulatory system Lining of small intestine (SEM) 14 Lung tissue (SEM) Interstitial fluid Nutrients 1 mm © 2014 Pearson Education, Inc. O2 Respiratory system ! Evolutionary adaptations such as specialized, extensively branched or folded structures, enable sufficient exchange with the environment (b) A hydra, an animal with two 13 layers of cells CO2 Animal body ! More complex organisms are composed of compact masses of cells with complex internal organization Exchange Food 250 µm ! In flat animals such as tapeworms, most cells are in direct contact with its environment Digestive system Anus Unabsorbed matter (feces) Excretory system Blood vessels in kidney (SEM) Metabolic waste products (nitrogenous waste) 50 µm Gastrovascular cavity Mouth 100 µm Mouth © 2014 Pearson Education, Inc. 12 © 2014 Pearson Education, Inc. 16 © 2014 Pearson Education, Inc. Figure 40.4a Figure 40.4b CO2 External Food O2 environment Mouth Animal body Figure 40.4c Figure 40.4d Respiratory system Interstitial fluid Heart Nutrients Digestive system Anus Unabsorbed matter (feces) Metabolic waste products (nitrogenous waste) Lung tissue (SEM) 17 © 2014 Pearson Education, Inc. 18 © 2014 Pearson Education, Inc. Blood vessels in kidney (SEM) 50 µm 100 µm Lining of small intestine (SEM) Excretory system 250 µm Cells Circulatory system 19 © 2014 Pearson Education, Inc. 20 © 2014 Pearson Education, Inc. Table 40.1 Table 40.1a Hierarchical Organization of Body Plans ! In vertebrates, the space between cells is filled with interstitial fluid, which allows for the movement of material into and out of cells ! Most animals are composed of specialized cells organized into tissues that have different functions ! A complex body plan helps an animal living in a variable environment to maintain a relatively stable internal environment ! Tissues make up organs, which together make up organ systems ! Some organs, such as the pancreas, belong to more than one organ system 21 © 2014 Pearson Education, Inc. 22 © 2014 Pearson Education, Inc. 23 © 2014 Pearson Education, Inc. 24 © 2014 Pearson Education, Inc. Table 40.1b Exploring Structure and Function in Animal Tissues Epithelial Tissue ! Different tissues have different structures that are suited to their functions ! Tissues are classified into four main categories: epithelial, connective, muscle, and nervous 25 © 2014 Pearson Education, Inc. ! It contains cells that are closely joined ! The shape of epithelial cells may be cuboidal (like dice), columnar (like bricks on end), or squamous (like floor tiles) 26 © 2014 Pearson Education, Inc. Figure 40.5a ! The arrangement of epithelial cells may be simple (single cell layer), stratified (multiple tiers of cells), or pseudostratified (a single layer of cells of varying length) ! Epithelial tissue covers the outside of the body and lines the organs and cavities within the body 27 © 2014 Pearson Education, Inc. 28 © 2014 Pearson Education, Inc. Figure 40.5aa Epithelial Tissue Stratified squamous epithelium Lumen Apical surface Connective Tissue Apical surface Basal surface Simple columnar epithelium Simple squamous epithelium 10 µm Basal surface Cuboidal epithelium Pseudostratified columnar epithelium ! Collagenous fibers provide strength and flexibility ! It contains sparsely packed cells scattered throughout an extracellular matrix ! Reticular fibers join connective tissue to adjacent tissues ! The matrix consists of fibers in a liquid, jellylike, or solid foundation ! Elastic fibers stretch and snap back to their original length Polarity of epithelia 29 © 2014 Pearson Education, Inc. ! There are three types of connective tissue fiber, all made of protein ! Connective tissue mainly binds and supports other tissues 30 © 2014 Pearson Education, Inc. 31 © 2014 Pearson Education, Inc. 32 © 2014 Pearson Education, Inc. Figure 40.5b Connective Tissue Blood Loose connective tissue ! Cartilage is a strong and flexible support material 55 µm 30 µm ! Fibrous connective tissue is found in tendons, which attach muscles to bones, and ligaments, which connect bones at joints 34 35 © 2014 Pearson Education, Inc. Figure 40.5bb Loose connective tissue Adipose tissue Central canal © 2014 Pearson Education, Inc. Figure 40.5ba Chondrocytes Bone Nuclei 700 µm 33 Osteon Fibrous connective tissue Bone Adipose tissue Nuclei Figure 40.5be Osteon 38 © 2014 Pearson Education, Inc. Fat droplets 150 µm 700 µm 120 µm 30 µm Central canal 37 36 Figure 40.5bd Collagenous fiber © 2014 Pearson Education, Inc. Fat droplets © 2014 Pearson Education, Inc. Figure 40.5bc Elastic fiber Red blood cells Chondroitin sulfate ! Bone is mineralized and forms the skeleton © 2014 Pearson Education, Inc. Cartilage Elastic fiber Fibrous connective tissue 100 µm ! Macrophages that are involved in the immune system ! Blood is composed of blood cells and cell fragments in blood plasma ! Loose connective tissue binds epithelia to underlying tissues and holds organs in place Plasma White blood cells 150 µm ! Fibroblasts that secrete the protein of extracellular fibers ! In vertebrates, the fibers and foundation combine to form six major types of connective tissue 120 µm ! Connective tissue contains cells, including Collagenous fiber ! Adipose tissue stores fat for insulation and fuel 39 © 2014 Pearson Education, Inc. 40 © 2014 Pearson Education, Inc. Figure 40.5bf Muscle Tissue Blood Cartilage Plasma Chondrocytes 100 µm 55 µm White blood cells ! It is divided in the vertebrate body into three types ! Muscle tissue is responsible for nearly all types of body movement ! Skeletal muscle, or striated muscle, is responsible for voluntary movement ! Muscle cells consist of filaments of the proteins actin and myosin, which together enable muscles to contract ! Smooth muscle is responsible for involuntary body activities ! Cardiac muscle is responsible for contraction of the heart Chondroitin sulfate Red blood cells 41 © 2014 Pearson Education, Inc. 42 © 2014 Pearson Education, Inc. Figure 40.5c 43 © 2014 Pearson Education, Inc. Figure 40.5ca 44 © 2014 Pearson Education, Inc. Figure 40.5cb Figure 40.5cc Muscle Tissue Skeletal muscle Nuclei Nuclei Sarcomere 100 µm Muscle fiber Smooth muscle Cardiac muscle Sarcomere Nucleus 100 µm Nucleus Muscle fibers 25 µm Nucleus Intercalated disk Muscle fibers Nucleus Intercalated disk 25 µm 25 µm 25 µm 45 © 2014 Pearson Education, Inc. Cardiac muscle Smooth muscle Skeletal muscle Muscle fiber 46 © 2014 Pearson Education, Inc. 47 © 2014 Pearson Education, Inc. 48 © 2014 Pearson Education, Inc. Figure 40.5d Figure 40.5da Video: Cardiac Muscle Contraction Neurons Neuron: Nervous Tissue Nervous Tissue Glia Neurons Neuron: Dendrites Cell body ! Nervous tissue contains 40 µm (Fluorescent LM) ! Glial cells, or glia, support cells 15 µm Cell body Axon Axons of neurons Axon ! Neurons, or nerve cells, that transmit nerve impulses Glia Blood vessel 40 µm ! Nervous tissue functions in the receipt, processing, and transmission of information Dendrites (Confocal LM) (Fluorescent LM) 49 © 2014 Pearson Education, Inc. 50 © 2014 Pearson Education, Inc. 51 © 2014 Pearson Education, Inc. Figure 40.5db Figure 40.6 Glia 15 µm Glia Figure 40.6a (a) Signaling by hormones Coordination and Control STIMULUS (a) Signaling by hormones STIMULUS Signal travels everywhere. Blood vessel ! A hormone may affect one or more regions throughout the body Cell body of neuron Signal travels to a specific location. Hormone Nerve impulse 53 Blood vessel Response 54 © 2014 Pearson Education, Inc. Nerve impulse Signal travels everywhere. Axons ! Hormones are relatively slow acting, but can have long-lasting effects © 2014 Pearson Education, Inc. STIMULUS Endocrine cell Axon Nerve impulse Hormone (Confocal LM) (b) Signaling by neurons STIMULUS Cell body of neuron ! The endocrine system transmits chemical signals called hormones to receptive cells throughout the body via blood Blood vessel (b) Signaling by neurons Endocrine cell ! Control and coordination within a body depend on the endocrine system and the nervous system Axons of neurons 52 © 2014 Pearson Education, Inc. Response Axon Signal travels to a specific location. 55 56 © 2014 Pearson Education, Inc. © 2014 Pearson Education, Inc. Concept 40.2: Feedback control maintains the internal environment in many animals Regulating and Conforming Figure 40.6b (a) Signaling by hormones Blood vessel (b) Signaling by neurons ! The nervous system transmits information between specific locations Nerve impulse ! Faced with environmental fluctuations, animals manage their internal environment by either regulating or conforming ! The information conveyed depends on a signal’s pathway, not the type of signal Axons ! A regulator uses internal control mechanisms to control internal change in the face of external fluctuation ! A conformer allows its internal condition to vary with certain external changes ! Nerve signal transmission is very fast ! Animals may regulate some environmental variables while conforming to others Response Response 57 © 2014 Pearson Education, Inc. 58 © 2014 Pearson Education, Inc. Figure 40.7 59 © 2014 Pearson Education, Inc. Figure 40.7a 60 © 2014 Pearson Education, Inc. Figure 40.7b Figure 40.7c 40 Body temperature (°C) River otter (temperature regulator) 40 Body temperature (°C) River otter (temperature regulator) 30 20 Largemouth bass (temperature conformer) 10 0 0 20 Largemouth bass (temperature conformer) 10 0 10 20 30 40 Ambient (environmental) temperature (°C) 61 © 2014 Pearson Education, Inc. 30 © 2014 Pearson Education, Inc. 0 10 20 30 40 Ambient (environmental) temperature (°C) 62 63 © 2014 Pearson Education, Inc. 64 © 2014 Pearson Education, Inc. Figure 40.8 Homeostasis Mechanisms of Homeostasis ! Organisms use homeostasis to maintain a “steady state” or internal balance regardless of external environment Animation: Negative Feedback ! Mechanisms of homeostasis moderate changes in the internal environment Thermostat turns heater off. Room temperature Room temperature increases. decreases. ! For a given variable, fluctuations above or below a set point serve as a stimulus; these are detected by a sensor and trigger a response ! In humans, body temperature, blood pH, and glucose concentration are each maintained at a constant level ROOM TEMPERATURE AT 20°C (set point) ! The response returns the variable to the set point Room temperature increases. Room temperature decreases. 66 67 © 2014 Pearson Education, Inc. © 2014 Pearson Education, Inc. © 2014 Pearson Education, Inc. Animation: Positive Feedback Feedback Control in Homeostasis Alterations in Homeostasis 68 © 2014 Pearson Education, Inc. ! Homeostasis in animals relies largely on negative feedback, which helps to return a variable to a normal range ! Positive feedback amplifies a stimulus and does not usually contribute to homeostasis in animals Core body temperature (°C) Figure 40.9 ! Set points and normal ranges can change with age or show cyclic variation Body temperature 60 36.9 40 20 36.7 36.5 ! In animals and plants, a circadian rhythm governs physiological changes that occur roughly every 24 hours Melatonin concentration 37.1 2 PM 6 PM 10 PM AM AM 10 0 AM Time of day Midnight Greatest muscle strength 6 AM Most rapid rise in blood pressure Fastest reaction time Noon 71 Lowest heart rate Lowest body temperature 6 PM 70 6 (a) Variation in core body temperature and melatonin concentration in blood Start of melatonin secretion 69 2 Melatonin concentration in blood (pg/mL) 65 Thermostat turns heater on. Highest risk of cardiac arrest 72 (b) The human circadian clock © 2014 Pearson Education, Inc. © 2014 Pearson Education, Inc. © 2014 Pearson Education, Inc. Body temperature Melatonin concentration 37.1 60 36.9 40 36.7 20 36.5 0 2 PM 6 PM 10 PM 2 AM 6 AM 10 Melatonin concentration in blood (pg/mL) Figure 40.9b Core body temperature (°C) Figure 40.9a © 2014 Pearson Education, Inc. Figure 40.10 Start of melatonin secretion Midnight Greatest muscle strength Lowest body temperature 6 AM 6 PM Most rapid rise in blood pressure Fastest reaction time AM Noon Time of day ! Homeostasis can adjust to changes in external environment, a process called acclimatization Lowest heart rate Highest risk of cardiac arrest (b) The human circadian clock (a) Variation in core body temperature and melatonin concentration in blood 73 74 © 2014 Pearson Education, Inc. © 2014 Pearson Education, Inc. Concept 40.3: Homeostatic processes for thermoregulation involve form, function, and behavior Endothermy and Ectothermy 75 © 2014 Pearson Education, Inc. 76 © 2014 Pearson Education, Inc. Figure 40.11 ! Endothermic animals generate heat by metabolism; birds and mammals are endotherms ! Thermoregulation is the process by which animals maintain an internal temperature within a tolerable range ! Endotherms can maintain a stable body temperature even in the face of large fluctuations in environmental temperature ! Ectothermic animals gain heat from external sources; ectotherms include most invertebrates, fishes, amphibians, and nonavian reptiles ! Endothermy is more energetically expensive than ectothermy ! In general, ectotherms tolerate greater variation in internal temperature (a) A walrus, an endotherm (b) A lizard, an ectotherm 77 © 2014 Pearson Education, Inc. 78 © 2014 Pearson Education, Inc. 79 © 2014 Pearson Education, Inc. 80 © 2014 Pearson Education, Inc. Figure 40.11a Figure 40.11b Variation in Body Temperature Balancing Heat Loss and Gain ! The body temperature of a poikilotherm varies with its environment ! The body temperature of a homeotherm is relatively constant ! Organisms exchange heat by four physical processes: radiation, evaporation, convection, and conduction ! The relationship between heat source and body temperature is not fixed (that is, not all poikilotherms are ectotherms) (b) A lizard, an ectotherm (a) A walrus, an endotherm 81 © 2014 Pearson Education, Inc. Figure 40.12 Radiation 82 © 2014 Pearson Education, Inc. Evaporation 83 © 2014 Pearson Education, Inc. Insulation Circulatory Adaptations ! Heat regulation in mammals often involves the integumentary system: skin, hair, and nails ! Insulation is a major thermoregulatory adaptation in mammals and birds ! Regulation of blood flow near the body surface significantly affects thermoregulation ! Five adaptations help animals thermoregulate ! Skin, feathers, fur, and blubber reduce heat flow between an animal and its environment ! Many endotherms and some ectotherms can alter the amount of blood flowing between the body core and the skin ! Insulation ! Insulation is especially important in marine mammals such as whales and walruses ! Circulatory adaptations ! In vasodilation, blood flow in the skin increases, facilitating heat loss ! Cooling by evaporative heat loss ! Behavioral responses ! In vasoconstriction, blood flow in the skin decreases, lowering heat loss ! Adjusting metabolic heat production Convection Conduction 85 © 2014 Pearson Education, Inc. 84 © 2014 Pearson Education, Inc. 86 © 2014 Pearson Education, Inc. 87 © 2014 Pearson Education, Inc. 88 © 2014 Pearson Education, Inc. Figure 40.13 ! The arrangement of blood vessels in many marine mammals and birds allows for countercurrent exchange ! Countercurrent heat exchangers transfer heat between fluids flowing in opposite directions and thereby reduce heat loss 1 Artery Cooling by Evaporative Heat Loss Bottlenose dolphin Canada goose 1 3 Vein Vein 35°C 33° 30° 27° 20° 18° 10° 9° 3 Artery 3 ! Some bony fishes and sharks also use countercurrent heat exchanges ! Many types of animals lose heat through evaporation of water from their skin ! Many endothermic insects have countercurrent heat exchangers that help maintain a high temperature in the thorax ! Sweating or bathing moistens the skin, helping to cool an animal down ! Panting increases the cooling effect in birds and many mammals 2 Key 2 89 © 2014 Pearson Education, Inc. Warm blood Cool blood Blood flow Heat transfer 90 © 2014 Pearson Education, Inc. 91 © 2014 Pearson Education, Inc. 92 © 2014 Pearson Education, Inc. Figure 40.14 Figure 40.15 Behavioral Responses Adjusting Metabolic Heat Production PREFLIGHT 40 ! Thermogenesis is the adjustment of metabolic heat production to maintain body temperature ! Some terrestrial invertebrates have postures that minimize or maximize absorption of solar heat ! Thermogenesis is increased by muscle activity such as moving or shivering ! Honeybees huddle together during cold weather to retain heat ! Nonshivering thermogenesis takes place when hormones cause mitochondria to increase their metabolic activity © 2014 Pearson Education, Inc. 94 © 2014 Pearson Education, Inc. Abdomen 30 Abdomen 25 0 2 Time from onset of warm-up (min) 95 © 2014 Pearson Education, Inc. Thorax 35 ! Some ectotherms can also shiver to increase body temperature 93 FLIGHT Thorax Temperature (°C) ! Both endotherms and ectotherms use behavioral responses to control body temperature PREFLIGHT WARM-UP © 2014 Pearson Education, Inc. 4 96 Figure 40.16 Figure 40.17 Results Acclimatization in Thermoregulation Thermostat in hypothalamus activates cooling mechanisms. Physiological Thermostats and Fever O2 consumption (mL O2/hr•kg) 120 ! Birds and mammals can vary their insulation to acclimatize to seasonal temperature changes 100 80 ! Thermoregulation in mammals is controlled by a region of the brain called the hypothalamus ! When temperatures are subzero, some ectotherms produce “antifreeze” compounds to prevent ice formation in their cells 60 5 10 15 20 25 30 Contractions per minute 35 97 © 2014 Pearson Education, Inc. 98 © 2014 Pearson Education, Inc. Figure 40.17a Body temperature decreases. NORMAL BODY TEMPERATURE (approximately 36–38°C) ! Fever, a response to some infections, reflects an increase in the normal range for the biological thermostat 20 0 Response: Sweat Body temperature increases. ! The hypothalamus triggers heat loss or heat generating mechanisms 40 0 Response: Blood vessels in skin dilate. Body temperature decreases. Body temperature increases. Response: Shivering ! Some ectothermic organisms seek warmer environments to increase their body temperature in response to certain infections 99 Response: Blood vessels in skin constrict. Thermostat in hypothalamus activates warming mechanisms. © 2014 Pearson Education, Inc. © 2014 Pearson Education, Inc. Concept 40.4: Energy requirements are related to animal size, activity, and environment Energy Allocation and Use 100 Figure 40.17b Thermostat in hypothalamus activates cooling mechanisms. NORMAL BODY TEMPERATURE (approximately 36–38°C) Response: Blood vessels in skin dilate. Response: Sweat Body temperature increases. Body temperature decreases. Body temperature increases. Body temperature decreases. Response: Shivering Response: Blood vessels in skin constrict. NORMAL BODY TEMPERATURE (approximately 36–38°C) ! Organisms can be classified by how they obtain chemical energy ! It determines how much food an animal needs and it relates to an animal’s size, activity, and environment ! Autotrophs, such as plants, harness light energy to build energy-rich molecules Thermostat in hypothalamus activates warming mechanisms. 101 © 2014 Pearson Education, Inc. ! Bioenergetics is the overall flow and transformation of energy in an animal 102 © 2014 Pearson Education, Inc. 103 © 2014 Pearson Education, Inc. Figure 40.19 Quantifying Energy Use Organic molecules in food External environment Animal body Digestion and absorption ! Metabolic rate is the amount of energy an animal uses in a unit of time Heat Energy lost in feces Nutrient molecules in body cells ! After the needs of staying alive are met, remaining food molecules can be used in biosynthesis Carbon skeletons ! Biosynthesis includes body growth and repair, synthesis of storage material such as fat, and production of gametes Cellular respiration ! Metabolic rate can be determined by Energy lost in nitrogenous waste ! An animal’s heat loss Heat ! The amount of oxygen consumed or carbon dioxide produced ATP ! Measuring energy content of food consumed and energy lost in waste products Biosynthesis Cellular work 105 104 © 2014 Pearson Education, Inc. Figure 40.18 ! Energy-containing molecules from food are usually used to make ATP, which powers cellular work ! Heterotrophs, such as animals, harvest chemical energy from food Heat Heat 106 107 © 2014 Pearson Education, Inc. © 2014 Pearson Education, Inc. © 2014 Pearson Education, Inc. Minimum Metabolic Rate and Thermoregulation Influences on Metabolic Rate Size and Metabolic Rate 108 © 2014 Pearson Education, Inc. Figure 40.20 ! Standard metabolic rate (SMR) is the metabolic rate of an ectotherm at rest at a specific temperature ! Some key factors are age, sex, size, activity, temperature, and nutrition ! Metabolic rate is proportional to body mass to the power of three quarters (m3/4) ! Smaller animals have higher metabolic rates per gram than larger animals ! The higher metabolic rate of smaller animals leads to a higher oxygen delivery rate, breathing rate, heart rate, and greater (relative) blood volume, compared with a larger animal ! Both rates assume a nongrowing, fasting, and nonstressed animal ! Ectotherms have much lower metabolic rates than endotherms of a comparable size 109 © 2014 Pearson Education, Inc. 110 © 2014 Pearson Education, Inc. 10 3 10 Dog Cat 1 10 −1 Rat Ground squirrel Shrew Mouse Harvest mouse 10 −2 10 −3 10 −2 10 −1 1 10 Shrew 7 Human Sheep 6 5 4 3 Harvest mouse 2 1 10 2 103 Body mass (kg) (log scale) (a) Relationship of basal metabolic rate (BMR) to body size for various mammals 111 © 2014 Pearson Education, Inc. 8 Elephant Horse 10 2 BMR (L O2/hr•kg) ! Metabolic rates are affected by many factors besides whether an animal is an endotherm or ectotherm BMR (L O2/hr) (log scale) ! Basal metabolic rate (BMR) is the metabolic rate of an endotherm at rest at a “comfortable” temperature Ground squirrel 0 10 −3 10 −2 Sheep Mouse Elephant Human Rat Cat Dog Horse 10 −1 1 10 10 2 103 Body mass (kg) (log scale) (b) Relationship of BMR per kilogram of body mass to body size 112 © 2014 Pearson Education, Inc. Figure 40.20a Figure 40.20b 103 Dog Cat 1 Rat Ground squirrel Shrew Mouse Harvest mouse 10−2 10−3 10−2 10−1 1 10 ! Activity greatly affects metabolic rate for endotherms and ectotherms 6 BMR (L O2/hr•kg) BMR (L O2/hr) (log scale) Human Sheep 10 Shrew 7 Horse 102 10−1 Activity and Metabolic Rate 8 Elephant 5 3 Harvest mouse 2 1 102 Sheep Elephant Human Cat Dog Horse Mouse Rat Ground squirrel 0 10−3 103 10 −2 10−1 1 10 102 ! The fraction of an animal’s energy budget devoted to activity depends on factors such as environment, behavior, size, and thermoregulation 10 3 Body mass (kg) (log scale) Body mass (kg) (log scale) (a) Relationship of basal metabolic rate (BMR) to body size for various mammals ! In general, the maximum metabolic rate an animal can sustain is inversely related to the duration of the activity 4 ! For most terrestrial animals, the average daily rate of energy consumption is 2–4 times BMR (endotherms) or SMR (ectotherms) (b) Relationship of BMR per kilogram of body mass to body size 113 © 2014 Pearson Education, Inc. 114 © 2014 Pearson Education, Inc. 115 © 2014 Pearson Education, Inc. 116 © 2014 Pearson Education, Inc. Figure 40.21 Torpor and Energy Conservation Results Day ! Torpor is a physiological state in which activity is low and metabolism decreases Relative RNA level (%) Per2 ! Torpor enables animals to save energy while avoiding difficult and dangerous conditions ! Hibernation is long-term torpor that is an adaptation to winter cold and food scarcity 100 60 ! There are also some fundamental similarities in the evolutionary adaptations of plants and animals 20 0 Euthermia Hibernation Euthermia Hibernation 118 Figure 40.22aa MAKE CONNECTIONS: Life Challenges and Solutions in Plants and Animals Environmental Response ! There are many aspects to the relationship between structure and function in animals 40 © 2014 Pearson Education, Inc. Figure 40.22a ! Summer torpor, called estivation, enables animals to survive long periods of high temperatures and scarce water ! Daily torpor is exhibited by many small mammals and birds and seems adapted to feeding patterns 80 117 © 2014 Pearson Education, Inc. Night Bmal1 119 © 2014 Pearson Education, Inc. Figure 40.22aaa Environmental Response 120 © 2014 Pearson Education, Inc. Figure 40.22aab Environmental Response Nutritional Mode Environmental Response Growth and Regulation An insect’s eyes contain photoreceptors that detect light. The floral head of a sunflower (left) and an insect’s eyes (right) both contain photoreceptors that detect light. 121 © 2014 Pearson Education, Inc. Figure 40.22ab Figure 40.22aba Nutritional Mode 123 © 2014 Pearson Education, Inc. Figure 40.22abb Nutritional Mode 124 © 2014 Pearson Education, Inc. Figure 40.22ac Growth and Regulation Nutritional Mode The broad surface of many leaves (left) enhances light capture for photosynthesis. When hunting, a bobcat relies on stealth, speed, and sharp 125 claws (right). © 2014 Pearson Education, Inc. The floral head of a sunflower contains photoreceptors that detect light. 122 © 2014 Pearson Education, Inc. The broad surface of many leaves enhances light capture for photosynthesis. © 2014 Pearson Education, Inc. When hunting, a bobcat relies on stealth, speed, and sharp claws. 126 127 © 2014 Pearson Education, Inc. In plants, hormones control growth patterns, flowering, fruit development, and more (left). In animals, hormones control developmental events such128 as molting (right). © 2014 Pearson Education, Inc. Figure 40.22aca Figure 40.22acb Figure 40.22b Figure 40.22ba MAKE CONNECTIONS: Life Challenges and Solutions in Plants and Animals Transport Reproduction Transport Growth and Regulation Growth and Regulation Gas Exchange Absorption In plants, hormones control growth patterns, flowering, fruit development, and more. In animals, hormones control developmental events such as molting. 129 © 2014 Pearson Education, Inc. Figure 40.22baa 130 © 2014 Pearson Education, Inc. © 2014 Pearson Education, Inc. Figure 40.22bab Transport 132 © 2014 Pearson Education, Inc. Figure 40.22bb Figure 40.22bba Reproduction Transport Plants harness solar energy to transport water, minerals, and sugars through specialized tubes (left). in animals, a pump (heart) moves circulatory fluid through vessels (right). 131 Reproduction Plants harness solar energy to transport water, minerals, and sugars through specialized tubes. 133 © 2014 Pearson Education, Inc. Figure 40.22bbb Seeds have stored food reserves that supply energy to the young seedling. 134 © 2014 Pearson Education, Inc. Figure 40.22bc Reproduction Milk provides sustenance for juvenile mammals. Figure 40.22bca Absorption 135 Figure 40.22bcb Absorption Absorption The villi (projections) that line the intestines of vertebrates increase the surface area available for absorption. 139 © 2014 Pearson Education, Inc. Figure 40.22bda 136 © 2014 Pearson Education, Inc. The root hairs of plants increase the surface area available for absorption. 138 © 2014 Pearson Education, Inc. Gas Exchange Seeds (left) have stored food reserves that supply energy to the young seedling, while milk provides sustenance for juvenile mammals (right). © 2014 Pearson Education, Inc. The root hairs of plants (left) and the villi (projections) that line the intestines of vertebrates (right) increase the surface area available for absorption. 137 © 2014 Pearson Education, Inc. Figure 40.22bd In animals, a pump (heart) moves circulatory fluid through vessels. Figure 40.22bdb Figure 40.UN01 Gas Exchange Gas Exchange Adélie penguin 4-kg male 340,000 kcal/yr In plants, highly convoluted surfaces have evolved, such as the spongy mesophyll of leaves. In both plants and animals, highly convoluted surfaces have evolved, such as the spongy mesophyll of leaves (left) and the alveoli of lungs (right). © 2014 Pearson Education, Inc. In animals, highly convoluted surfaces have evolved, such as the alveoli of lungs. 142 © 2014 Pearson Education, Inc. Basal (standard) metabolism 143 © 2014 Pearson Education, Inc. Deer mouse 0.025-kg female 4,000 kcal/yr Ball python 4-kg female 8,000 kcal/yr Key Reproduction 141 140 © 2014 Pearson Education, Inc. Thermoregulation © 2014 Pearson Education, Inc. Activity Growth 144 Figure 40.UN02 Figure 40.UN03 Figure 40.UN04 NORMAL RANGE for internal variable Response Hibernating dormouse (Muscardinus avellanarius) Control center 145 © 2014 Pearson Education, Inc. Stimulus: change in internal variable Sensor 146 © 2014 Pearson Education, Inc. 147 © 2014 Pearson Education, Inc.