SNC1
Ecosystems
1) What is an ecosystem?
2) What is a population?
3) What is a community?
4) What is a species?
5) List as many was that can think of that different species might be related.
6) How do we know what different species eat? List as many ways that you can think of.
7) Look at the definitions of each of the following types of organisms.
Give two examples of each type.
Herbivore
Carnivore
Omnivore
Producer
Primary Consumer
Secondary Consumer
Tertiary Consumer
Scavenger
Decomposer
Predators
Prey
Top Carnivore
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8) What sort of organism are you. Use as many terms as are appropriate.
9) Give some examples of your prey.
SNC1
Food Chains
A diagram that shows the organisms in an ecosystem. Each organism has only one food source
and has only one other species eat it.
—>
trees
1) Which species is a:
—>
deer
Consumer
Producer
Herbivore
Carnivore
wolf
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2) a) If you could measure the mass of all of the trees in a forest, all of the deer, and all of the
wolves, which would have: the most total mass? _____________________
the least total mass? _____________________
b) Why?
3) Hint:
a) How much food (in kilograms) do you eat every day (estimate)?
b) How much would this total up to in one year?
c) What is your body mass?
d) How much weight have you gained over the last year?
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e) What is b) minus d)
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f) What happened to all of this extra mass of food?
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g) What happens to most of the food energy that you eat each year?
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h) Divide the mass of all the food you eat by your body mass
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i) Do you think that there will be a similar relationship between the total mass of all the
individuals of a certain species of consumer and the total mass of the individuals of the species
that it eats?
4) There are 100 wolves living in a forest. The deer that the wolves eat are 3 times as heavy as
the wolves. The trees that the deer eat are 2 times as heavy as the deer.
a) How many deer must be living in the forest?
b) How many trees must be living in the forest?
5) If a disease were to kill off all or most of the wolves, what would happen to:
a) the deer population
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b) the tree population
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6) If a disease were to kill off all or most of the deer, what would happen to:
a) the wolf population
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b) the tree population
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7) Why is it important for an animal to have more than one prey species and more than one
species that preys on it.
8) Which of the species in the tree-deer-wolf food chain is a top carnivore?
9) a) What happens to all of the waste materials of the trees, deer, and wolves as well as all of
the wolves, deer, and trees that are not killed and eaten? What kind of organisms are involved?
b) What would happen if these organisms were not present in the ecosystem?
10) a) Make a food chain out of the following species?
b) Describe each species with all of the appropriate terms from the list.
Snake
Grass
Toad
Hawk
Grasshopper
c) What type of organism is missing from this list?
d) If there is 10 million kilograms of grass in a forest, how many top carnivore individuals
can there be?
Terms
Herbivore - an animal that eats plants.
Carnivore - an animal that eats other animals.
Omnivore - an animal that eats both plants and animals eg bears and humans.
Producer - an organism that produces its own food by photosynthesis
Primary Consumer - Animals that consume only plants.
Secondary Consumer - Animals that eat primary consumers .
Tertiary Consumer - Animals that eat secondary consumers (other carnivores ).
Scavenger - a consumer that eats dead animals.
Decomposer - an organism such as bacteria and fungi that breaks down dead
organisms and their wastes materials. They do not 'eat' food like scavengers.
Instead they break down solid matter into liquids which they can absorb.
Predators - kill other animals for food.
Prey - are the organisms that predators feed on.
Top Carnivore - an animal that no other species of animals kill for food.