How do an increase in the organic matter in soil and an increase in soil depth affect the population of plants in an area? A Larger plants become the dominant organisms. B Mosses replace flowering plants. C Nitrogen-fixing bacteria kill young trees. D Grasses become diseased.

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.