As animals move up in the food chain they start to have larger competition for food with other animals, deer compete with elk and even rodents that eat the same food as them. They must fight for food and survival.
Answer:
a regulatory substance produced in an organism and transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action.
Explanation:
The answer is A, 'a mammal' because it goes with the copulative verb 'to be', i. e., 'is'.
The cytoplasm is the peanut butter in a PB&J sandwich—it holds the sandwich (cell) together
