Food Chains, Food Webs, And The Transfer Of Energy

Food Chains, Food Webs, andthe Transfer of Energy

What is Ecology?Ecology is the scientific study of interactions betweendifferent organisms and between organismsand their environment or surroundings

Every organism has a habitat and a niche.A habitat is all the aspects of the area in which an organism livesbiotic (living) factors such as trees, animalsabiotic (non-living) factors such as water, soil, sun, windWhere are you from?A niche includes all of the physical, chemical, and biologicalfactors that a species needs to survive, stay healthy, and reproduce.What do you do? (behavior)What do you eat / how do you eat?Are you the top predator?You can think of a habitat as where a species livesand a niche as how it lives within its habitat. Niche Video

All can live in the area because they occupy a different ecological niche

How are organisms classified in anecosystem?What they eat or how they get theirfood (producers, consumers, anddecomposers).

The Producers (Autotrophs) A group of organisms that can use the energy insunlight to convert water and carbon dioxide intoGlucose (food) through photosynthesis. Theymake /produce their own food. Sunlight is the main energy source for life onearth The chemical formula for photosynthesis is:

The Producers (Autotrophs) Autotrophs are also called Producers becausethey produce all of the food that heterotrophsuse Without autotrophs, there would be no life onthis planet Ex. Plants and Algae

The Consumers (Heterotrophs)Organisms that do not make their own food can be referred to asconsumers, they consume other organisms for their energy andfood supply.Ex. Rabbits, Deer, Mushrooms

Consumers (Heterotrophs)Scavengers/Detritivores – feed on the tissue of deadorganisms (both plants and animals) Ex. – Vultures, Crows, and Shrimp

The Consumers (Heterotrophs)Herbivores – eat ONLY plants Ex. – Cows, Elephants, Giraffes

The Consumers (Heterotrophs)Carnivores – eat ONLY meat Ex. – Lions, Tigers, Sharks

Heterotrophs – the ConsumersOmnivores – eat BOTH plants and animals Ex. – Bears and Humans

DecomposersDecomposers – absorb any dead material and breakit down into simple nutrients or fertilizers Ex. – Bacteria and Mushrooms

Feeding Interactions between organism –Energy Flow and the Food ChainEnergy flows through an ecosystem in one directionfrom the sun or inorganic compounds to autotrophs(producers) and then to heterotrophs (consumers)

FOOD CHAINSFood Chain—series of steps in which organisms transfer energy byeating and being eaten. Start with producer and end with topconsumer or carnivore**The sun is the initial source ofeaglesnakefrogenergy for food chains.Keep in mind that the arrow tipalways points towards the“eater”. The direction of howenergy is transferred. .eatergrasshoppergrassfood

Food Chains Question: Which direction does thearrow points ? Answer: It points to the direction of theenergy transfer, NOT “what ate what” Question: What is the primary source ofenergy for life on earth? Answer: The Sun

FOOD CHAINSBroken down intoproducers and consumers.cannot makeSince theytheir own food, they mustconsume othereat or “ ”organisms.eaglesnakefrogbasis ofThey form thealmost all food chains.They use the energy insunlightto make theirown food through a processphotosynthesiscalled .grasshoppergrass

FOOD CHAINSThere are different levelsof consumers .Top carnivore: any organism that isnot hunted by any other. It’s at thetopof its food chain.eagle quaternary consumerThe4th consumer in a food chain.It eats tertiary.consumerssnake tertiary consumerThe 3rdconsumer in a food chain.consumersIt eats secondary.frog secondary consumerThe 2ndconsumer in a food chain.It eats primary.consumersgrassprimary consumerhopper1st consumer in a food chain.TheproducersIt eats .grass

All organisms eventually die anddecompose.FOOD CHAINSeagleDetritus: is the wastematterand rottingremains of deadorganisms.snakefrogdetritusgrasshoppergrassThe cycle restarts.Decomposers: areeatorganisms thatdetritus and breakit down into.nutrientsdecomposersnutrientsNutrients: are substancesneeded for an organism’sgrowth and .repair

Let’s THINKWhat would happen if there were nodecomposers?

HUMANS AND FOOD CHAINSHave you ever eaten one of these?What is it made of?wheatWhat food chains did youparticipate in when you ate this?tomatocheesebeefonionlettuce

FOOD WEBSNo ecosystem is onlymade up of only onefood chain. Mostorganisms eat morethan JUST oneorganism.Members ofWhen you connect all.the food chains ofdifferent organismsfrom one ecosystemtogether, you form.

Create a Food Web Form groups of 3, create a basic food web for each ofthe following habitats.– Freshwater wetland– Forest

What are Trophic Levels? The Energy movement from one organisms toanother when it is eaten Each step in this transfer of energy is known as atrophic level

TROPHIC LEVELSIt is the position an organism occupies in a food chain. Eachlink in the chain represents one tropic level. The first trophiclevel starts with the producers.eagle5th trophic levelsharksnake4th trophic levellarger fishfrog3rd trophic levelsmall fishgrasshopper2nd trophic levelzooplanktongrass1st trophic levelphytoplankton

TROPHIC LEVELSAs organisms eat one another,energy is transferred up the foodchain.—eagle 0.1 kcalonly about 10% of the available- 0.9 kcal energy within a trophic level istransferred to the next highersnake 1 kcaltrophic level- 9 kcalThis 10 % is used to buildfrog 10 kcalbiomass as well as to provide- 90 kcal energy for bodily functionsgrassThis means that 90 % of the100 kcalhopperenergylost, in the form ofenergy ismostly- 900 kcal detritus and as heat used inmetabolic processes.grass 1000 kcal

With your group, pick one foodchain for your habitat and create atrophic level.

The _ consumer in a food chain. It eats _. 1st 2nd 3rd 4th producers primary consumers secondary consumers tertiary consumers any organism that is There are different levels _not hunted by any other. top Top carnivore: is the _ and _ of dead organisms. FOOD CHAINS grass grass- hopper frog snake eagle All organisms eventually .