All the living things in an ecosystem have a role to play. Plants
are producers. Inside their green leaves they have round discs
called chloroplasts. They are in stacks called grana. A green
substance called chlorophyll fills the chloroplasts. It is what gives
plants their green color. The chloroplasts allow plants to use water,
sunlight and carbon dioxide to produce their own food. That’s why
they are called producers.
When an animal eats a plant, energy that the plant got from
the sun is transferred to the animal. An animal that eats plants is
called an herbivore. Since it is the first animal in the food chain, it
is also the primary consumer. A consumer is an animal that eats
plants or other animals. Consumers that eat only other animals
are called carnivores. Consumers that eat both plants and animals
are called omnivores.
Producers are critical to the survival of all living organisms
in an ecosystem. Consumers depend on producers for the food
which gives them energy. None of the other living things in the
ecosystem would survive for long without producers.
Many plants make seeds by combining pollen from their
flowers with pollen from other flowers. Water or wind occasionally
help pollen get where it needs to go. Sometimes it is carried by
animals, especially birds and insects.
Since some animals eat plants, it makes sense that animals
sometimes help plants to reproduce, or make more plants. These
animals that help plants reproduce by carrying pollen from one
plant to another are called pollinators. Larger animals often
help plants reproduce without even realizing it. Some seeds are
caught in animal fur or eaten with fruit from the plants. The animal
carries seeds from one place to another so plants can spread
to new places. The seeds are deposited and grow in their new
locations. Carrying and scattering plant seeds so they will have
the opportunity to expand to new areas is called seed dispersal.