Transcript What is a food chain?

Web of Wildlife
Food and Food Chains
• All living things need food to survive.
– Organisms obtain their food in different ways.
− Some animals eat plants, some eat other animals.
• The feeding relationships between animals and plants
in a habitat can be described with a food chain.
• Can you think what these words mean?
PREDATOR
Lion
PREY
Thomson’s gazelle
• Can you think what these words mean?
CARNIVORE
Cheetah
HERBIVORE
Koala
• What about this word?
OMNIVORE
What is a food chain?
• Food chains show what eats what in a particular habitat.
• All food chains start with a PRODUCER.
Grass
Rabbit
Fox
What is a food chain?
PRODUCER: An organism, usually a green plant, that uses
photosynthesis to turn sunlight, water and carbon dioxide
into sugars (energy). AUTOTROPH
Grass
CONSUMER: an animal in a food
chain that eats (consumes) a plant
or another animal. HETEROTROPH
Grass
Rabbit
Fox
Decomposers
• Can be fungi or
bacteria
•Eat dead organisms
•They prevent too
much decay and
enrich the soil with
nutrients, saprophyte
• Break up bodies of
dead organisms into
smaller pieces
• Help decomposers
manage dead
organisms, faster
decomposition
• Do not return
nutrients to soil
Scavengers
What is a food chain?
• The links between animals and plants in a habitat can be
demonstrated by drawing a food chain.
• Food chains show how energy found in food moves
through a community.
Grass
What do you think the arrow
means between the pictures?
Rabbit
Fox
The arrow in a food chain means
‘is eaten by’ and ‘provides
energy to’.
Why do all organisms need
energy?
 Growth
 Repair damaged parts
 Replace cells at end of
life cycle
Grass
Rabbit
PRIMARY CONSUMER
Fox
SECONDARY CONSUMER
TERTIARY CONSUMER
Coyote
10 C = PRIMARY CONSUMER: An animal at the second
level in a food chain which feeds on the producer. Primary
consumers are usually herbivores, feeding on plants and
fungi.
20 C = SECONDARY CONSUMER: An animal at the third
level in a food chain. Secondary consumers can be
carnivores or omnivores.
30 C = TERTIARY CONSUMER: An animal at the fourth level
of a food chain. This is usually the top level, and tertiary
consumers are usually carnivores and prey on other animals.
A simple British woodland
food chain
Food chains show how energy found
in food moves through a community.
CONSUMER
20 C
CARNIVORE
PREDATOR
CONSUMER
10 C
HERBIVORE
PRODUCER
PREY
Sparrowhawk
A Food Web is a series of
food chains that represent
energy flow through an
ecosystem.
Fox
Lizard
Hawfinch
Rabbit
Grasshopper
Grass
Sparrowhawk
A British woodland
‘food web’
Fox
Lizard
Hawfinch
Rabbit
Grasshopper
Grass
Energy in an Ecosystem
http://videos.howstuffworks.com/discovery/27995-assignment-discovery-energy-flow-video.htm
Food Chains - YouTube
Energy Pyramid - Energy Flow in Ecosystem -Video for Kids by makemegenius.com - YouTube
Changes to food chains
• INTERDEPENDENCE
• Animals and plants depend on each other for survival.
Common toad eating young grass snake
Grass snake eating common toad
• If something changes at one level in a food chain, it can
affect all other levels in the food chain too.
If a pesticide killed all the
grasshoppers….
Sparrowhawk
Hawfinch
Grasshopper
Grass
…what would happen
to everything else in
the food chain?
Questions to think about…
• What happens if the producer in a food chain dies?
• What happens if one of the consumers in a food chain
dies?
– How does this affect the other species that prey on it?
– How does this affect the other species that it preys on?
Activity
• Split into groups
• You will be assigned a habitat – Arctic tundra, the
Antarctic, British coastal waters, British woodland or
African savanna.
• Using the worksheet, describe your habitat, what the
weather is like and the animals and plants you think
might be found there.
• You will then be given species information cards for your
habitat, along with photographs of some of the species
that are found there.
• Using the information on the cards and the arrows
provided, make the food chain for your habitat.
• Rotate around the room - you will have the chance to
build food chains for each different habitat.
HERBIVORE: an animal which only eats plants.
Koala
Rabbit
CARNIVORE: an animal which eats meat (other
animals).
Cheetah
Fox
OMNIVORE: an animal that feeds on both plants and
other animals.
Producer
PRODUCERS  Plants are
called producers because
they make (produce) their
own food.
Consumer
CONSUMERS  Animals are
called consumers because
they eat (consume) other
plants and animals.
• Can you think of any animals that eat plants?
• Can you think of any animals that eat other animals?
• How do plants get their food?