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Ch. 7 Animal Adaptations to the Environment *Adaptations Animals Must Make for Their Environment: 1. Acquisition & digestion of food 2. Maintenance of body temp. 3. Maintenance of water balance 4. Adaptations to variation in light I. Acquiring Energy & Nutrients A. Animal Use of Plants 1. The ultimate source of energy for ALL animals is . 2. Animals must convert plant tissue into animal tissue. *Animals are high in proteins, but plants are low in proteins. B. Animal Classification Based on Food Source 1. - feed only on plant tissue. EX: ??? 2. - feed only on other animals. EX: ??? 3. - feed on both plant & animal tissues. EX: ??? 4. - feed on dead plant & animal matter. EX: ??? C. Mouth Parts 1. Piercing Mouthparts EX: mosquito 2. Chewing mouthparts EX: grasshopper 3. Strong conical beak EX: cardinal 4. Straining Beak EX: flamingo 5. Tearing beak EX: raptors 6. Grinding molars EX: deer 7. Canine/Shearing teeth EX: coyote D. Herbivory *Types of Herbivores: 1. - feed only on leafy materials, such as grasses. EX: ??? 2. - feed on woody material. EX: ??? 3. - feed on seeds. EX: ??? 4. Frugivores- feed only on fruit. 5. Avian sapsuckers- feed on plant sap. 6. Nectivores- feed on nectar. EX: ??? Grazers & Browsers Granivores & Frugivores Sapsuckers & Nectivores E. Grazers & Browsers 1. Diets are high in indigestible cellulose. 2. Depend on special & protozoans to digest the cellulose. * - process of converting sugars into inorganic acids & alcohols anaerobically. * 2 Types of Digestive Tracts: 1. Foregut fermentors/Ruminants- have a 4-compartment stomach & chew regurgitated cud. EX: cow & deer *4 Guts: rumen, reticulum, omasum, & abomasum 2. Hindgut fermentor/Nonruminant- have long intestines & well- developed caecum. EX: horses & termites a. caecum- pouch attached to the colon where fermentation takes place. *Other Types of Herbivores: 1. Lagomorphs- ingest fecal material for further digestion. (corpography) EX: rabbits & hares 2. Seed-eating Birds- have 3 separate stomach chambers. EX: chickens, pigeons, & doves *3 Chambers: a. - pouch in the esophagus that holds food before passing to the stomach. b. - secretes enzymes to begin digestion. c. - contains small pebbles to grind the food. * Some coral, algae-eating fish use a similar mechanism. F. Carnivory *Do not have to worry about digestion of cellulose, so the tract is . 1. Mammals: stomach stores & mixes food. 2. Birds: small gizzards that catch bones, hair, & feathers to be regurgitated. G. Omnivory 1. Food habits vary with seasons, stage of their life cycle, & size & growth rate. EX: Red fox- berries, apples, cherries, acorns, grasses, grasshoppers, crickets, beetles, & small rodents II. Animals Have Various Nutritional Needs A. Mineral & Amino Acids Needed 1. Animals require many minerals such as K, Ca, Na, Mg, ect… 2. Animals also require 20 amino acids. a. nonessential amino acid- made by the body. b. essential amino acid- must be supplied by the diet. B. Quality & Quantity of Nutrients *3 Things Animals Might Suffer From When Nutrients Are Low: 1. Malnutrition 2. Leaving their habitat 3. Starvation *3 Things That May Happen When Nutrient Quality Is Low: 1. Poor reproduction 2. Poor health 3. Lifespan 1. The plants highest in quality are those high in nitrogen such as growing leaf tips & buds. 2. This is why most animals have offspring in the spring. III. Affects of Mineral Availability On Growth & Reproduction A. Sodium Deficiency 1. Herbivores usually get an inadequate supply of sodium because their diets consists of vegetation only, which is low in sodium. EX: deer, cows, & elephants 2. Mineral licks are used to supplement the sodium. IV. Animals Require Oxygen To Release Energy Stores in Food A. Aerobic Respiration 1. Animals release energy stored in food primarily by aerobic respiration, which requires . B. Ways of Taking In Oxygen: 1. Diffusion across the skin (cutaneous respiration) EX: some salamanders 2. Small openings called spiracles in the body wall. EX: insects & arachnids 3. Lungs EX: mammals, birds, & reptiles 4. Both lungs & cutaneous respiration EX: frogs & turtles 5. Gills EX: fish & amphibian larvae V. Regulation of Internal Conditions A. - maintenance of a relatively constant internal environment despite changing external environment. 1. Negative Feedback System- when a system changes from a normal state, the organism restores the system to a regular state. EX: thermostat & sweating VI. Exchange of Energy With Their Surroundings *Animal heat regulation differs from plants because they can produce heat by metabolism & can move to seek heat & cold. A. Animal Body Structure 1. Body Surface Temp.- differs from the surrounding air temp. a. Contains hair, feathers, scales, muscle, fat, ect… 2. Core body temp. is higher than the surface. VII. Three Groups of Animals Based on Temp. Regulation A. 3 Temp. Regulation Groups: 1. - maintain a fairly constant body temp. independent of external temperatures. EX: ??? 2. - acquire heat from the external environment. EX: ??? 3. - regulate body temp. by endothermy & ectothermy. EX: bats, bees, & hummingbirds VIII. Poikilotherms Depend on Environmental Temps. A. Changes in Metabolism With Temp. Changes 1. For every 10°C the temp. rises, the metabolic rate . 2. When temp. fall, activity . B. Maintenance of Constant Body Temp. 1. Poikilotherms maintain a constant body temp. by seeking & . EX: basking & burrowing C. Aerobic vs. Anaerobic 1. During normal daily activity, poikilotherms use respiration. 2. During stressful situations & while pursuing prey, they use respiration. IX. Homeotherms Escape Environmental Restraints A. Maintenance of High Body Temps. 1. Homeotherms maintain high body temps. by burning energy. 2. 3 forms of insulation in homeotherms: fur, feathers, & fat 3. Mechanisms for body temp. maintenance: shivering, sweating, & panting X. Endothermy & Ectothermy Trade-offs A. Advantages of Endothermy: 1. Can remain active at all times. 2. Can maintain large body masses. B. Advantages of Ectothermy: 1. Do not have to use energy to maintain body temp. 2. Can survive long periods of time without eating or drinking. XI. Heterotherms A. Insects 1. Insects are . 2. In the adult stage, flying insects may be heterothermic. 3. While flying, they have a very high metabolism, so they are homeothermic. 4. Most insects cannot fly unless their body temp. is between 30-44°C. 5. They must warm up before flight. XII. Torpor & Conserving Energy A. Torpor Def: temporary periods of inactivity during unfavorable environmental conditions in which animals greatly reduce their metabolic rate. EX: hummingbirds, bats, & mice 1. Nocturnal = torpor during the day 2. Diurnal = torpor at night B. Hibernation Def: winter dormancy in animals characterized by very low metabolism. EX: groundhogs, chipmunks, reptiles, & amphibians *Bears do not go into true hibernation. 1. Decrease body temp., heart rate, respiration, & oxygen levels. 2. Feed heavily in the summer or store food for the winter. XIII. Physiological Means of Thermal Balance A. Supercooling- body temps. fall below freezing without actually freezing. EX: Arctic marine fish & some reptiles *Some species actually freeze & thaw out when they wake up. B. Countercurrent heat exchange- conserves heat in vital parts of the body during cold situations. XIV. Maintenance of Water Balance A. Water Balance 1. Water makes up about - % of living things. 2. Water loss must be offset by uptake from the environment. 3. Gain water by: eating, drinking, & respiration. 4. Lose water by: urine, feces, & evaporation from skin. XV. Aquatic Animal Water Balance A. Freshwater vs. Saltwater 1. Freshwater: a. - have a high salt concentration in their body. 2. Marine: a. - have a low salt concentration in their body. b. Must try to keep salt levels high to prevent dehydration. XVI. Buoyancy of Aquatic Organisms A. Mechanisms For Buoyancy: 1. - regulates the amount of gas to increase or decrease buoyancy. 2. Some have high levels of lipids under the skin, which is less dense than saltwater. EX: sharks, mackerel, & seals XVII. Influence of Light & Dark Cycles A. Internal Biological Clock Def: animals natural response to changing light. (Circadian Rhythm) 1. Influences hormones that play a role in sleep, metabolic rate, & metabolism. XVIII. Animal Activity Influenced By Light & Dark A. Classification of Animals Based on Light/Dark Cycles: 1. - are not controlled by day length but some other factor. 2. - stimulated by shorter day lengths. 3. - stimulated by longer day lengths. *Day length stimulates growth, reproduction, migration, ect… XIX. Marine Organisms Follow Tidal Cycles A. Tidal Cycle 1. Based on the lunar cycle which lasts 24.8 hrs. 2. Tides change every 12.4 hrs. *Organisms become active & inactive based on the changing of tides.
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