Answer:
Plants are called Producers because they can produce food energy. Animals are called Consumers because they can only consume food energy. Animals that eat plants are called Herbivores or Primary Consumers. Animals that eat other animals are called Carnivores.
Explanation:
The growth of plants and formation of land mammals characterized the paleozoic era.
Antibiotics added to livestock feed have been found to increase their growth rate, reduce incidence of infection, reduces mortality and improve feed conversion ratio or feed efficiency.
The correct answer is indicator species.