S7L4a
Demonstrate in a food web that matter is transferred from one organism to
another and can recycle between organisms and their environments.
FOOD WEBS MATTER
THE ENERGY CYCLE AT WORK
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As animals eat grass, the nutrients contained in the grass
are broken down into their chemical components and
then rearranged to become living deer tissue
Waste products are produced in the animal’s digestive
system and pass from the deer’s body back into the
ecosystem.
Organisms break down this waste into simpler chemical
components
The grass growing close by is able to take up those
components and utilize them; they become a part of the
grass
The cycle begins again.
FOOD CHAINS AND FOOD WEBS
The producers, consumers and decomposers
of each ecosystem make up a food chain.
 Energy flow through an ecosystem occurs in
food chains, with energy passing from one
organism to another.
 There can be many food chains in an
ecosystem.
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consumers
producer
decomposers
PRODUCERS
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Producers of an ecosystem use abiotic (non
living) factors to obtain and store energy for
themselves or the consumers that eat them.
 Trees, bushes, shrubs, small plants, grass,
moss
CONSUMERS
Members of the ecosystem that depend on
other members for food
 Each time that a plant or animal consumes
another organism, energy transfers to the
consumer.
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 Deer,
foxes, rabbits, raccoons, owls, hawks, snakes,
mice spiders, insects
THREE TYPES OF CONSUMERS
Herbivore-animals that eat only plants
 Omnivore-animals that eat both plants and other
animals
 Carnivore-animals that eat only other animals
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Saprophyte-organisms that obtain food from dead
organisms or from the waste products of living
organisms
Decomposers are members of the ecosystem that use
dead or decaying organisms as a source of energy.
They further reduce organic matter to its simplest
chemical components.
 They include fungi and bacteria
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The interaction of many food chains is a food
web.
 Most producers and consumers interact with
many others, forming a complex food web out
of several simple food chains.
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Predator is any organism that feeds on other
living things, typically animals, but also insects
and plants.
 Prey is the organism that it feeds on.
 Predator and prey together help maintain an
ecological balance within their ecosystem.
 This balance benefits the community as a
whole, but can be either helpful or harmful to
the individuals that make up the community,
depending upon whether they are the predator
or the prey.
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