3. tributyrin agar has a shelf life of only a few days before it loses its opacity. a. with this in mind, explain the importance of positive and negative controls in this test. b. how would expired tributyrin agar affect the results of lipase-positive and lipase-negative organisms

An ecologist studied the same species of deer during the summer and the winter. she noticed that during the summer, when there was plenty of food, the deer were energetic and playful. however, during winter when food was scarce, the deer moved more slowly and did not run unless they needed to escape a predator. which scientific fact is best supported by her observations?

Tropical rain forests support more species per unit area than any other terrestrial ecosystem. what is one way rain forests are important to the health of the biosphere?

Awolf pack hunts,kills, and feeds on a moose. in this interactions, the moose is a?