module 7 Flashcards
surface area
rate of exchange
volume
rate of use/production
as surface area increases
size increase and volume increases
surface area increase and ability to exchange
ability to exchange quicker
SA to volume ratio increases
in smaller organisms, better oxygen in and out, obtains nutrients faster
SA to volume ration decreases
in larger organisms, limited oxygen in and out, refrain from loosing heat
A convulted surface
increases the surface area of the organisms
animals require oxygen
most organisms are increase what
most organisms are oxygen regulators, increase surface area
oxygen in water is
-oxygen less soluble in water
as temp increases solubility of oxygen
decreases
concurrent flow
maintain gradient by water flowing opposite the way blood flows
herbivores
feed on plants
carnivore
feed on flesh
detrivores
feed on non living organic matter
animals can respond to evironment variations in two ways
conform
regulate
Conformers
changes in external environment cause parallel changes in body
unable to maintain consistent internal conditions different than the external environment
conformers ability to survive depends on
depends on its range of tolerance to internal changes
Regulators
changes in external environment do not cause internal changes
able to maintain consistent internal conditions
Different than external environment
over a broad range of environmental conditions
Conformity Benefits
low energetic expenditure
mechanisms to maintain a consistent internal environment not needed
conformity costs
If environmental conditions are not optimal
Can lead to reduced activity, growth, reproduction
Regulation
benefits
and costs
Benefits Greatly extended range of environmental conditions for: Activity Growth Reproduction Increased level of performance
Costs
Usually energetically expensive
Homeostasis
depends on
Maintenance of a relatively constant internal environment in a varying external environment
Depends on negative feedback
Wia= Wd + Wf + Wa - We – Ws (+ Wm)
Wia= Animal’s internal water Wd = Drinking Wf = Food Wa = Absorbed from air We = Evaporation Ws = Secretion / Excretion Wm = Metabolic Water
Metabolic water
refers to the water released during cellular respiration.
more concentrated urine
less water loss
less concentrated urine
more water loss
estivation
Some animals in arid regions enter estivation
avoid effects of drought through a period of dormancy (physiological inactivity)
Spadefoot toads in the desert
southwest
If two environments differ in water or salt concentrations,
Substances will tend to move
osmosis
Substances will tend to move down their concentration gradients.
Diffusion
Osmosis:
Diffusion of Water through a semipermeable membrane.
Isosmotic
Body fluids and external fluid are at the same concentration.
Hypoosmotic
Body fluids are at a higher H20 (lower salt) concentration than the external environment.
Hyperosmotic
Body fluids are at a lower H20 (higher salt) concentration than the external environment.
Marine Invertebrates
Isomotic organisms
Sharks, skates, rays
Hyperosmotic to seawater.
Marine bony fish
Strongly hypoosmotic
Freshwater Fish and Invertebrates
Hyperosmotic organisms
and lose salt
Poikilotherms
Body temperature varies directly with environmental temperature.
Homeotherms
maintain a relatively constant internal environment.
Ectotherms
Rely mainly on external energy sources.
Endotherms
Rely heavily on metabolic energy.
Ectothermy
Reliance on external sources to maintain body temperature Used to: Elevate Body Temperature Solar Radiation Conduction of heat from warm surface Reduce body temperature Reducing rate of Temperature Increase Shade Conduction of heat to cooler substance
Endothermy
Use of elevated metabolism in response to body cooling to maintain body temperature
Usually for homeothermy
Cooling
Shivering
Heating
Increased activity
Also reduction in body temperature in stress periods
homeothermy
Homeothermy
Maintenance of a constant body temperature
Usually warmer than Environment
“Warm-Blooded”
Poikilothermy
Poikilothermy
Failure to regulate body temperature
Conformance to environmental Temperature
“Cold-Blooded”
Advantages of Homeothermy
Constant rate of chemical processes
Processes optimized
Can live in wider Range of environments
Disadvantages of Homeothermy
Poikilothermy more
Requires Energy to maintain Homeostasis
Poikilothermy can give better survival during stress periods – Flexibility
Regulatory
Short-term Response
Changes in Physiological rates and Behavior
Utilize Existing Adaptations & Morphology
Acclimation
Longer-term physiological or morphological
Reversible
-seasonal changes
Developmental
Response to Slow Changes
Lead to Genetic or Morphological Changes
Not Reversible
HS = Hm ± Hcd ± Hcv ± Hr - He
HS = Total heat stored in an organism Hm = Gained via metabolism Hcd = Gained / lost via conduction Hcv = Gained / lost via convection Hr = Gained / lost via electromag. radiation He = Lost via evaporation
Basal Metabolic Rate (BMR)
resting metabolic rate
Metabolic rate of an organism that is resting quietly and in postabsorptive state.
Similar to Resting Metabolic Rate (RMR)
Minimal metabolic rate
Thermal neutral zone
Range of environmental temperatures over which metabolic rate of homeothermic animal does not change.-metabolic rate constant
Breadth
Indicates tolerances
Varies among endothermic species.
Lower Critical Temperature
Lowest Temperature an organism is able to maintain body temperature without additional metabolism
Depends on BMR & Conductance
Temperature ↓ = Heat loss ↑
Lower Temperatures Require Additional Heat Production
Limited by ability to gather Food
Lower Critical Environmental Temperature
Temperature at which metabolism can not support gathering of food and maintenance of body temperature
Must use body stores. must use fat
Lower Critical Physiological Temperature
Temperature at which metabolism can no longer produce enough heat to compensate for heat loss
Survival limited by rate of heat loss & maximum metabolic rate.
Upper Critical Temperature
Highest Ambient Temperature at which an organism is able to maintain body temperature without additional metabolism
Depends on BMR & Conductance
Higher temperatures require additional energy for heat dissipation
Limited by ability to dissipate heat without producing excess heat
Allen’s Rule
Certain extremities of animals are relatively shorter in cooler parts of a species’ range than in warmer parts.
Bergmann’s Rule
Geographic races of a species possessing smaller body size are found in the warmer parts of the range, and races of larger body size in cooler parts.
Gloger’s Rule
Dark pigments increase in races of animals living in warm and humid habitats.
Torpor
Temporary condition of lowered body temperature and inactivity
Decreased Heart Rate
Decreased Metabolism
Slowed or Missing Reactions
Hummingbirds enter a state of torpor when food is scarce and night temps are extreme
Extended Torpur
Hibernation - Winter
Estivation - Summer
Surviving Extreme Temperatures
Inactivity Seek shelter during extreme periods Utilize Microclimates Minimize Gradients Reduce Exposure Huddling Curling Puffing
Energy Conservation Adaptations
Decreasing Gradients
Insulation – Fur, Feather, Fat
Movements
Shuttling – Alternating locations to maintain body Temperature
Aquatic Environments
Mostly Ectothermic
Endothermic responses
Limited to a few Species
Countercurrent Flow
Maintains Core Temperature
Surface Considerably Cooler
Allows Rapid Adjustment to Environment
Core systems relatively constant
almost all plants are what
poikilothermic ectotherms.
