Microscopic life in the soil can play many roles, both positive and negative. Which of the following combinations of soil life would usually be the best choice to ensure long-term sustainable agriculture?
O nematodes and symbiotic bacteria
O microscopic non-animal life, plus earthworms
O sterile soil free of nematodes
O all broad classes of microbiota in balance

The health, management and conservation of biodiversity, is a challenge facing ecosystems worldwide. the major factors that affect the health and function of the great barrier reef are climate change and pollution. which question investigates the effects of a biotic factor on the reef ecosystem?

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Categorize each term as something that is typical of a scientific theory, a scientific hypothesis, or both. makes predictions