cool link Trophic Level The trophic level of

cool link

Trophic Level: The trophic level of an organism is the position it occupies in a food chain. The word trophic derives from the Greek τροφή (trophē) referring to food or feeding. A food chain represents a succession of organisms that eat another organism and are, in turn, eaten themselves.

Energy Allocations… sunlight or food in (energy source) energy stored in biomass stays in the organism energy stored in waste energy used/”lost” in metabolism leaves the organism equal What is available for the next trophic level ? (or for an organism that eats another organism? ) the biomass

sunlight or food in (energy source) energy stored in biomass stays in the organism energy stored in waste energy used/”lost” in metabolism leaves the organism equal What is available for the next trophic level ? (or for an organism that eats another organism? ) the biomass What happens to some energy every time an organism eats another organism? some is transformed to thermal energy (heat) and “lost” to the universe

What happens to some energy every time an organism eats another organism? some is transformed to thermal energy (heat) and “lost” to the universe

please sir…

survival depends on available food plants “eat” : CO 2 (from atmo) H 2 O (from ground) nutrient (from ground) ils, the (the na he for building wood, t on) carbohydrates insulati protein fats amino acids…. animals “eat” : (th plants other animals e ha for energy mm er) to build to do to re-build (repair) … ergy n e w/o build no x no fi o no d u…. o no y

93, 000 , 00 0 m iles 0. 0000095% of light emitted from Sun reached Earth warms planet photosynthesis allows us to see solar panels electricity

cool link consider a “short” food chain…. grass grows cow eats grass human eats cow 0. 58 lbs of CO 2 (let the glucose represent the complex structure of grass) 0. 40 lbs of C 6 H 12 O 6 0. 24 lbs of H 2 O 0. 42 lbs of O 2 the biomass 670 Cal / 0. 40 lbs C 6700 al 10 % of the energy in is stored in the biomass 20% is “excreted” in waste 70% is used to build / do (metabolism)

consider a “short” food chain…. grass grows cow eats grass human eats cow (let the glucose represent the complex structure of grass) the biomass 670 Cal / 0. 40 lbs al C 6700 10 % of the energy in is stored in the biomass 20% is “excreted” in waste 70% is used to build / do (metabolism) one standard cow needs to eat 9000 lbs hay / year (2 acres of grass) 15 0 , 00 0, 0 00 C al the biomass of grass 15, 000 Cal / 9000 lbs

consider a “short” food chain…. grass grows cow eats grass human eats cow the biomass of grass 15, 000 Cal / 9000 lbs one standard cow needs to eat 9000 lbs hay / year (2 acres of grass) 150 , 0 Cal 0 0 00, 0 average cow weighs 1500 lbs (the biomass of the cow) provides, say, 800 lbs of “steak” 1000 Cal / lb steak so, 800, 000 Cal of food energy available ~10 % of the energy in is stored in the biomass ~20% is “excreted” in waste ~70% is used to build / do (metabolism)

the biomass of grass 15, 000 Cal / 9000 lbs consider a “short” food chain…. grass grows cow eats grass human eats cow one standard cow needs to eat 9000 lbs hay / year (2 acres of grass) 150 , 0 Cal 0 0 00, 0 0 lb) 0 0 9 ( s average cow weighs 1500 lbs f gras o s e r c w 2 a lb co 0 (the biomass of the cow) 0 5 1 it takes e n o d s e r e to f lb pe 0 5 1 e n o to feed provides, say, 800 lbs of “steak” 1000 Cal / lb steak so, 800, 000 Cal of food energy available 2000 Cal / day (to do and to build) yr) standard 150 lb human ( d/ 5 6 3 750, 000 Cal / year

~10 % of the energy in is stored in the biomass ~20% is “excreted” in waste ~70% is used to build / do (metabolism) waste 300, 000 Cal waste 3, 000 Cal waste 30, 000 Cal 150, 000 Cal biomass 1, 500, 000 Cal biomass 15, 000 Cal metabolism 1, 050, 000 Cal metabolism 10, 500, 000 Cal metabolism 105, 000 Cal