Food chains and food webs
Lesson objectives
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To compare natural food chains.
To construct food chains and food webs.
Some organisms seems unnecessary and
harmful. But if they die other organisms may
also die. How this can be explained?
Ecosystem
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Organisms living in the same
area interacting with abiotic
factors form ecosystem.
Living organisms depend on
each other by nutritional
relationships and make food
chains.
Food Chains
A food chain is a simple model that shows
how food (energy) flows from one
organism to another.
What are producers?
● Producers are organisms that use energy from the sun
to make their own food through a process called
photosynthesis.
● A producer as an organism that produces its own
food.
● Most producers are plants.
What are consumers?
● A consumer is a living that cannot make its own food.
Consumers get their energy by eating food. All
animals are consumers.
● Examples: cows, hawks, wolves, fish & even people!
● DG Discussion: Can you think of any examples of
PRODUCERS? List 5 on your copybooks.
Primary consumers
● Primary consumers are consumers that
eat producers (plants).
Secondary consumers
● Secondary consumers are consumers that
eat primary consumers.
Tertiary consumers
Tertiary consumers are consumers that eat
secondary consumers.
Food Webs
▪ A food web is a
model that shows
many food chains
and pathways in
which energy (food)
flows through a
group of organisms.
Let’s do an activity on p.10
Homework
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Read 10-11
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New words
Literacy questions on
p.11
Research time