Organisms and their environment

Name: __________________ Topic: Organisms and their environment LO: Briefly describe the non-cyclical nature of energy flow ● Energy flows in alinear manner. It does not flowin a cycle. Hence energy cannotbe recycled.● Chemical energy is transferred from one trophic level to another upon predationand finallyreleased as heat.● Energy flow can be represented by a food chain:Producers(plants)primaryconsumer (herbivore)secondary consumer (carnivore)tertiary consumer(carnivore / omnivore) LO:Explainthetermsproducer,consumerandtrophiclevelinthecontextoffoodchains and food webs ● Foodchain:aseriesoforganismsthroughwhichenergyistransferredintheformof food.● Food web is made up of many interconnecting food chains. Concepts Summary NotesNan Hua High School Biology 1

Name: __________________ Topic: Organisms and their environment ● Trophiclevel:feedingpositioninafoodweborchain,beginningwithproducersat trophic level one.● Producer:Organism,whichproducestheir own food,glucosethroughphotosynthesisbyabsorbinglightenergyandconvertingitintochemicalenergyin food.Producersarethefirstorganismsin thefoodchainorfoodwebandoccupy the first trophic level.● Consumer: Organism thatobtains energy by feedingon other organisms. Eg: Concepts Summary NotesNan Hua High School Biology 2

Name: __________________ Topic: Organisms and their environment LO:Explainhowenergylossesoccuralongfoodchains,anddiscusstheefficiency of energy transfer between trophic levels ● As energy is passed on from one trophic level to another, 90% of it is lostasheatenergy due to respirationandchemical energy in excretedor egested wasteproductssuch as uneaten body parts, faeces, etc.● Only10% of energy stored as tissuesis transferredto the next trophic level.● Theshorter the food chain, the less energy is lostto the environment. Hencemore efficient in energy transfer. Concepts Summary NotesNan Hua High School Biology 3

Name: __________________ Topic: Organisms and their environment LO: Describe and interpret pyramids of numbers and biomassPyramid of numbers● Allowsforcomparisonofthenumberoforganismspresentineachtrophiclevelat a particular time.● Can be inverted (narrow – based) or upright (broad-based). Pyramid of biomass● Allowsforthecomparisonofthedrystandingmassoforganismspresentineachtrophic level at a particular time.● Mostly upright (broad–based)● Canbe invertedif the producerreproducesfastenoughto supporttheconsumersdespite theirsmaller biomass at any onetime. Concepts Summary NotesNan Hua High School Biology