Which of the following resources is used directly to make plastics? A. coal
B. natural gas
C. sunlight
D. oil

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important

Amarine ecologist has constructed the conceptual model shown in the diagram. what predictions can be made from using this model? where the tertiary consumers get their energy how often primary producers are able to reproduce when bacteria and fungi initiate the process of decomposition whether other secondary consumers are present

How have crops been modified? a.plants have been made more susceptible to pests b.plants have been made resistant to herbicides c.plants have been made more susceptible to herbicides d.plants have been modified to have reduced yield