Good Science Victorian Curriculum Year 7

BIOLOGICAL SCIENCES
3.1
PRODUCERS,
CONSUMERS
AND
DECOMPOSERS
LEARNING INTENTION
At the end of this lesson I will
be able to describe the roles
of producers, consumers and
decomposers in an ecosystem.
KEY TERMS
carnivore
an organism that eats only
animals
consumer
an organism that gains energy
by consuming other organisms
decomposition
the process of rotting and decay
herbivore
an organism that eats only
plants
omnivore
an organism that eats both
animals and plants
producer
an organism that produces
energy at the start of a food
chain
LITERACY LINK
VOCABULARY
Produce is a verb, but can be
changed to a noun by adding
an ‘r’ at the end. This is the
same with consume(r) and
decompose(r). Think of a list of
words that can be changed from
verbs to nouns by adding an ‘r’
at the end.
1
2
All organisms within an ecosystem, including humans, depend
on interactions with each other for energy, nutrients and
survival. Food chains and webs show the feeding relationships
between producers, consumers and decomposers.
Producers create their own energy
All energy that enters into a food chain will initially come from the sun.
In order to harness this energy and pass it along a food chain, the first
organism in a food chain must always be a producer.
Producers can ‘produce’ their own energy and are most commonly
plants. Plants (and other organisms that can photosynthesise) harness
the Sun’s energy in a process called photosynthesis.
In photosynthesis, water and carbon dioxide are chemically changed
into glucose (the sugar energy source) and oxygen.
What is an example of a common producer?
Consumers get nutrients from other
organisms
Consumers are so named because they ‘consume’ something else in
order to get their energy. They can’t create their own energy using the
Sun like producers can, so they need to eat (or consume) something else.
If consumers only eat producers they are herbivores, which only eat
plants. If they only eat other consumers they are carnivores, which only
eat animals. And if consumers eat both producers and other consumers
they are omnivores, which eat both plants and animals.
In a food chain, the primary consumer is the consumer that eats the
producer. The consumer that eats the primary consumer is called the
secondary consumer, and so on.
What is the main difference between omnivores
and carnivores?
Figure 3.1
This rainbow lorikeet
is a consumer,
feeding on the nectar
of red bottlebrush
flowers.
36 GOOD SCIENCE VICTORIAN CURRICULUM 7