Answer:
Lets start with the food chain, which is a series of organisms each dependent on the next as a source of food. Food chains start with a produce, an organism that is able to make its own food (ex: plant). Another name for a producer is an autotroph. Then an organism eats the plant, which would be considered the primary consumer, then that organisms is eaten by another organism, the secondary consumer, and then another organism eats that organism, tertiary consumer. All organisms that must consume another organism for their food is called a heterotroph, or consumer. The primary consumer, which always eats the producer could also be called a herbivore, because producers are plants, and a herbivore is an animal that only eats plants. An animal that only eats other animals are called carnivores, which mean that they only eat meat. And an animal that eats both plants and animals would be called an omnivore.
The following shows 3 different food chains. In the first one corn is our producer, which is eaten by a mouse (the primary consumer), and the mouse is eaten by the owl (the secondary consumer). The second food chain is little longer, therefore showing the tertiary consumer, which is the lion in this example. If you notice the arrows are pointing in the direction of energy travel. The mouse gets the energy from the corn, and the owl gets the energy from the mouse. The corn goes into the mouse's stomach, and the mouse goes into the owl's stomach.
Step-by-step explanation: