How have humans changed the global nitrogen cycle? A. They have greatly decreased the amount of fixed nitrogen.
B. They have raised the speed at which nitrogen travels through the
cycle.
C. They have lowered the speed at which nitrogen travels through the
cycle.
D. They have greatly increased the amount of fixed nitrogen.

Compare and contrast the relative importance of the sporophyte vs gametophyte generation between nonvascular plants (bryophytes), seedless vascular plants and seed plants, and explain the ecological significance of a larger sporophyte generation

Which statements best describe the differences or similarities between a comparative investigation and an experimental investigation? check all that apply. experimental investigations are best for showing cause-and-effect relationships, while comparative investigations do not necessarily show this type of relationship. comparative investigations are often impractical and unrealistic, while experimental investigations are the most practical and realistic kinds of investigations. comparative investigations allow for the use of a wide range of variables but do not have a control group, while experimental investigations involve variables that can be controlled. both experimental investigations and comparative investigations are designed to answer scientific questions. both experimental investigations and comparative investigations focus on making observations rather than collecting new data.

Dan made the table shown to describe two different relationships between animals. organism interactions relationship a relationship b one organism lives inside the organism it feeds off no organism is harmed which of the following statements is most likely correct?