The prey of one species might also be the predator of another species. select the best answer from the choices provided t f 19pts

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.

Hydrilla (hydrilla verticillata) is an invasive aquatic plant and one of the most serious aquatic pests in florida. hydrilla has already been introduced to hundreds of bodies of water throughout florida, hydrilla is difficult to control because it grows rapidly and survives in many different water depths and conditions. hydrilla • describe how hydrilla affects native plant and animal species. include both a biotic and an abiotic limiting factor. • suggest one biotic and one abiotic recommendation that could slow the spread of hydrilla

The us council on environmental quality, the world wildlife fund of the united states, the ecological society of america, the smithsonian institution, and the international union for the conservation of nature have proposed four principles of wildlife conservation. which of the following does not apply to wildlife conservation? a) continuous monitoring, analysis, and assessment b) ecosystem maintenance that includes wildlife c) a plan encompassing entire communities of organisms and all renewable resources d) a continued interest in harvesting populations for sport