BIO 373 1st Edition Lecture 6 Outline of Last Lecture I. Freshwater Biological Zonesa. Lotic systemsb. Lentic systemsc. Human impactII. Marine Biological Zonesa. Intertidal regionsb. Coral reefc. Pelagic zoned. Human impactIII. Texas biomesIV. Temperature Variation and Water Availability a. Physiological ecologyOutline of Current Lecture I. Temperature Variation and Water Availability continueda. Plantsb. Animalsc. Ectothermsd. Endothermse. Variation in Water Availibilityi. Water potentialf. Water Balance in terrestrial plantsCurrent LectureTemperature Variation and Water Availability- Temperature Variation in Plantso When transpiring, plants give off heat, internal temperature decreases Drop leaves to regulate temperature- Tradeoff= less photosynthesis, less energy production AlternativesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Hairs on leaveso Provides reflectance- Guard cells- Adjust thickness of boundary layerso Smaller boundary layer, heat exchanged easily (in warmer environments)- More coloro Absorb more heat- More layers of leaveso Thicker boundary layer, can hold on to more heat when wind passes or temperatures are low- Temperature Variation in Animalso Surface area to volume ratio Larger objects have lower surface area to volume ratio- Increase surface area and maintaining volume will decrease surface are to volume ratio- Temperature Variation in Ectothermso Microhabitat selection Ex: burrowing—when too hot or too cold Ex: frogs crystallize internal liquids and produce more solutes, freeze theiroutsides, to keep internal of cells aqueous- Temperature Variation in Endothermso Mammals and birds, bees and fish tooo Metabolic heat Can produce a lot of heat with muscle activity Good endurance athletes—can maintain burst of energy for a longer period of timeo Tradeoff of endothermy: highly energetically costly Limited by resources like foodo Small endotherms have higher metabolic rates Small organisms lose heat quickly so must have a very high metabolic rateto maintain heat- Ex: humming birdso Torpor= state of physical inactivity - Variation in Water Availabilityo Marine environments are hyperosmotic  More salinity than organismso Freshwater are isosmotico Water potential = potential for water to do work Water potential= osmotic potential + pressure potential + matric potential- Osmotic potential= a negative value, concentration of solutes, lessavailability with solutes present- Pressure potential= turgor pressure- Matric potential= negative, related to attraction forces of something to water Moves from high potential to low potential More solutes, increased osmotic potential, decreased water potential- Water Balance in Terrestrial Plantso Amount of water in soil is determined by inputs, outputs, texture, topographyo Soil can capture water with adherence Sandy soil—bigger particles Clay soil—smaller particles- Bigger particles, lower surface area to volume ratio, decreased matric potential- Smaller particles, increased matric, decreased availability for organismso Daytime: movement of water in soil to plants Plants photosynthesize during the day and transpire- Gradient of water potential (higher in soil than plant) Stomata= minute pores in the epidermis of the leaf or stem of a plant, forming a slit of variable width that allows movement of gases in and out of the intercellular spaces.o Adaptations More roots—looking for water Protrude roots for