BIO 105 1st Edition Lecture 2 Ecosystem- an association of organisms and their physical environmentTrophic Levels- Producers( plant-autotrophs) are closest to the energy input and are the FIRST TROPHIC LEVEL-Q: What is the typical energy transfer between trophic levels?<20%- Number of trophic levels in an ecosystem 4-5 levelso WHY?  not enough energy  Biological Magnification- A non degradable or slowly degradable substance becomes more and more concentrated in the tissues of organisms at higher trophic levels of a food web- Ex: We get concerned about high levels of mercury Biogeochemical Cycles- Main reservoir for the nutrient is in the environment 3 Components, 4 Cycles, 4 Reservoirs- Hydrologic Component1. Water Cycle- ocean main reservoir- Atmospheric Component2. Nitrogen Cycle- atmosphere main reservoiro Nitrogen fixation- fixing bacteria on plants and in ground convert nitrogen gas into ammonia3. Carbon Cycle- sediments and rocks main reservoiro Carbon is the major ingredient in all organic moleculeso Atmospheric carbon is mainly carbon dioxide- Sedimentary ComponentThese 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.4. Phosphorous Cycle- earth’s crust main reservoir (only one without an “atmospheric component- most prevalent limiting factor in ecosystems) Important: 75% of earth covered by water , 93% salt water, 51% of U.S. water contaminated Green House Effect- Greenhouse gases impede the escape of heat from Earth’s surface-excessive CO2 in upper atmosphere trapping heat and gasesAnimal Behaviors and The Environment- Lecture 4 Innate Behavior- behavior performed in same way by all individuals of a species Fixed Action Pattern- stereotyped response- ex: wasp goes to circular shape Learning- response that change with experience Imprinting-Triggered by exposure to simple sign stimulus- ex: geese hatchlings treat the first moving object they see as their mother Sign Stimulus- causes Starling Nest Decoration- Starling line nest with wild carrot, carrots protected nest and birds from mites- mites takeover without wild