Biology 200B 1st EditionExam # 2 Study Guide Chapters 42-45Chapter 42 Animal Form and FunctionAdaptations - heritable traits that allow individuals to survive and reproducein a certain environment better than individuals that lack those traitsFitness trade-offs - inescapable compromises between traitsAcclimatization - reversible responses to environmental fluctuations The ability to acclimatize is an adaptation itself.Tissues - groups of cells that function as a unitConnective tissue - consists of cells that are loosely arranged in a liquid, jellylike, or solid matrix (loose, dense, supporting, fluid)Nervous tissue - consists of nerve cells, neurons, and several types of supporting cellsneurons - transmit electrical signals, produced by changes in the permeability of the cell’s plasma membrane to ionsMuscle tissue - functions in movement of the body, pumping of the heart, and mixing of food in the gastrointestinal tract (skeletal, cardiac, smooth)Epithelial tissue - covers the outside of the body, lines the surface of organs,and forms glands; apical side, basolateral side, basal lamina Organs - tissues organized into specialized structuresOrgan system - groups of tissues and organs that work together to perform one or more functionsAs an animal gets larger, its volume increases much faster than its surface area.As size increases, mass specific metabolic rate must decrease, or the surface area available for exchange of materials would fail to keep up with metabolic demands generated by the organism’s enzymes.Adaptations that increase surface area: -Flattening - gill lamellae-Folding - villi-Branching - capillariesHomeostasis - stability in the chemical and physical conditions within an animal’s cells, tissues, and organs-can be achieved by two processes: 1. conformation 2. regulationAnimals have a set point for blood pH, blood oxygen and nutrientconcentrations, and other parameters.3 general components:1. sensor - structure that senses some aspect of the external/internal environment2. integrator - evaluates the incoming sensory info and “decides” whether a response is necessary to achieve homeostasis 3. effector - any structure that helps restore the desired internal conditionnegative feedback - effectors reduce or oppose the change in internal conditionMechanisms for heat exchange:Conduction - direct transfer of heat between two physical bodies contact with one anotherConvection - heat transferred between a solid and a moving liquid or gasRadiation - transfer of heat between two bodies that are not in direct physical contactEvaporation - phase change that occurs when liquid water becomes a gasThermoregulation - controlling of body temperatureEndotherm - produces adequate heat to warm its own tissuesEctotherm - relies on heat principally gained from environmentHomeotherm - keep body temp. constantHeterotherm - allow body temps. to rise or fall depending on environmental conditionsChapter 43 Water and Electrolyte Balance in AnimalsOsmoregulation - process by which living organisms control the concentration of water and electrolytes in their bodiesDiffusion - net movement of substances from regions of higher concentration to lower concentrationsOsmosis - diffusion of water Selectively permeable - membrane that some solutes can cross more easily than others; phospholipid bilayerConcentration gradient - along which the net movement of ions and molecules occursOsmoconformers - seawater nearly matches the normal electrolyte concentrations found within these animalsIsosmotic - solute concentrations equal inside and outsideOsmoregulators - actively regulate osmolarity inside their bodies to achieve homeostasisHyperosmotic - solution inside body contains fewer solutes than does the solution outsideHyposmotic - solution inside body contains more solutes than the outsideFigure 43.1Passive transport - driven by diffusion along an electrochemical gradient, does not require expenditure of energy in the form of ATP- occurs through channels or carrier proteins; facilitated diffusionActive transport - occurs when source of energy such as ATP powers the movement of a solute to establish an electrochemical gradient-sodium-potassium pump, cotransporter/symporter/antiporter, aquaporinsNitrogenous wastes:Ammonia (NH3) - toxic to cells, at high concentrations raises the pH of intracellular and extracellular fluids enough to poison enzymesUrea - excreted in urine, enzyme-catalyzed reactions convert ammonia to a much less toxic compound; mammalsUric acid - terrestrial arthropods, nitrous, and other reptiles; reactions convert ammoniaTerrestrial insects: spiracles and trachea - insect tracheal system connects with the atmosphereat openings called spiraclesTo maintain homeostasis, insects must carefully regulate the composition of a blood-like fluid called hemolymph - pumped by the heart and transports electrolytes, nutrients, and waste productsMammalian kidneys: -know ureter, bladder, urethra, nephron, cortex, medullaFiltration - filtering large volumes from the blood allows waste to be removed effectively; renal corpuscleReabsorption - selectively retrieves small substances that are valuable, pumps and cotransporters in the proximal tubule reabsorb nutrients, electrolytes, and water but leave wasteCreating Osmotic Gradient - loop of Henle; fluid that emerges from proximaltubule enters this (Figure 43.15)Regulating water and electrolyte balance - distal tubule and collecting duct (Figure 43.17)Chapter 44 Animal Nutritionnutrient - a substance that an organism needs to remain aliveEssential nutrients - nutrients that cannot be synthesized and must be obtained by the diet-essential amino acids-vitamins -minerals-electrlytesMouthparts: capturing food1. suspension feeders2. deposit feeders3. fluid feeders4. mass feedersAdaptations of mouthparts - the cichlid jaw (example of adaptive radiation)Ingestion - process of bringing food into the digestive tractDigestion - breakdown of foodAbsorption - uptake of specific ions and molecules across the membrane of the digestive tract Digestive tracts:1. Incomplete - one opening, for both ingesting and eliminating waste2. Complete - two openings, start at mouth and end at anus(pg 889-896)Digestion starts at mouth - salivary amylase, lingual lipase, salivary glands, mucusPeristalisis moves material down the esophagus - muscle contractions, cropStomach - muscles called sphincters, stomach acid, parietal cells, mucous cells, carbonic anhydrase, ulcer, ruminants