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Learning Goals By the end of this lesson, you should: Know the difference between a producer (autotroph) and a consumer (heterotroph) Know the different types of consumers Know how to draw a food chain and food web Know how to create a food web from several food chains and derive food chains from a food web Understand why food chains are generally limited to four links

Producers and Consumers Producers (Autotrophs) Organisms that carry out photosynthesis Convert the suns energy into useable chemical energy Plants, algae and some other organisms

Consumers (Heterotrophs) Organisms that eat other organisms to obtain energy because they cannot produce their own energy.

Consumers (Heterotrophs) Trophic levels of consumers Primary Consumer Eat producers Grasshoppers, Deer, Moose Secondary Consumer Eat Primary consumers Robins, Small snakes, Frogs Tertiary Consumers Eat Secondary Consumers Foxes, Wolves,

Consumers Consumers can further be classified as to what type of tissues they eat Herbivore Only eat plant tissue Deer, Moose Carnivores Eat mostly animal tissue Wolves, Coyotes Animals that hunt and kill other animals are called predators; the animals they kill are the prey. An animal can be a predator to a smaller animal and prey to a larger one.

Consumers Scavengers Carnivores that eat the tissue of animals they did not kill Vultures Omnivores Eat plant and animal tissue Most humans, Bears, Racoons

Consumers Decomposers Special group of consumers that break down organic matter and release the nutrients back into the ecosystem. They do not eat the organic material directly; they release enzymes which break it down which they then absorb. Fungi and bacteria Detritivore Consumers that feed on Organic Matter The remains of dead organisms and animal waste Snails, worms, maggots.

Food Chains The easiest way to display feeding relationship is with a food chain illustrates who eats whom in an ecosystem always begins with a producer A food chain also shows how energy passes through an ecosystem e.g. chemical energy stored in pine seeds is passed through a red squirrel to a weasel and ends up in a goshawk

Food Webs Food chains do not exist in nature. Feeding relationships are much more complicated in reality Animals do not just eat one thing and often several species will all eat a type of food (e.g. grass) A more accurate way to illustrate this is with a food web A food web represents the feeding relationships within a community by showing the interconnectedness of several food chains

Food webs Some organisms may play more than one role by changing consumer levels. A large number of different food sources for each organism helps to reduce the vulnerability of that organism to the loss or decline of one food source e.g if the blueberry bush disappeared from the above food web, the snowshoe hare would not die off because it still has other food sources

Energy Pyramids Shows the amount of available energy the producers and consumers contain as energy flows through the ecosystem 60 % of energy contained in food passes through animals as waste 30 % is used for cellular respiration 10 % is used to make, bone, muscle, and fat.

Energy Pyramids Only 10 % of the energy consumed is passed on to the next consumer. The more levels there are between the producer and final consumer the less energy is left over.

Learning Goals By the end of this lesson, you should: Know the difference between a producer (autotroph) and a consumer (heterotroph) Know the different types of consumers Know how to draw a food chain and food web Know how to create a food web from several food chains and derive food chains from a food web Understand why food chains are generally limited to four links

Homework Read pp. 30 – 32 Answer the following questions: p. 35 # 1, 3, 7, 9, 11, 13, 15