Standard 2a Students
know plants are the primary source of matter and energy entering most food
chains
Standard 2b Students
know producers and consumers (herbivores, carnivores, omnivores, and
decomposers) are related in food chains and food webs and may compete with each
other for resources in an ecosystem
1. Review
Last week you
learned how plants and animals help each other survive.
Which animal is
most likely to disperse the seeds found in berries?
caterpillar
bee
bird
For
which of the following do many plants depend on animals?
photosynthesis shelter seed dispersal
2. What is a food chain?
Every living organism needs energy
to live. Plants get their energy from the Sun, some
animals get their energy from eating plants, and other animals
get energy from eating other animals. A food chain is a way of
organizing living things by what they eat. It shows who's
eating who. The arrows in a food chain show the flow of
energy.
Everything in the food chain is
either a producer or a
consumer.
Now you know that
food chains begin with plants (producers). Plants are a
primary source in food chains; that
means they are at the beginning of the food chain.
Anything that eats plant or animals is called a consumer.
There are 3 types of consumers
herbivore
carnivore
omnivore
Think Time...
Which do you think has the best chance of surviving during tough times?
herbivore carnivore omnivore
4. Animal and Plant
Survival
If
something on the food chain disappears it causes a problem for all the
other animals on the food chain.
For
example, if the grass dies because there isn't enough rain then
the deer won't have enough food to eat. If the deer
starve, then the carnivores that eat them will also go hungry.
If birds
disappear, then the insects that they normally eat will
increase. The insects will then eat too much of the plant
life, causing a shortage of food for other plant eaters.
This is a
food web. Like a food chain,
it shows the flow of energy. It starts with a primary
source, a producer. It shows two consumers that eat the
producer, the mouse and the grasshopper.
If all
the snakes were eaten, which animal will most quickly be threatened by
starvation?
If all
the snakes were eaten, which animal population would most likely
increase?