An organism that obtains energy and nutrients by feeding on other organisms or their remains. A food web is a model of the feeding relationships between many different consumers and producers in an ecosystem. Without plants (the primary producers) consumers and decomposers would not be able to live. Producers always start every food chain. A consumer, also called a heterotroph, is an organism that cannot make its own food. It must eat producers or other organisms for energy.
It is the independent variable. Because it can have an effect on the dependent variable.
Answer:
nuclei, mitochondria and chloroplasts
