Think about how sedimentary rocks form. can you determine which fossils in the image are the oldest and which fossils are the youngest? explain your answer.

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.

All organisms contribute some water to the water cycle by conducting

Restless tectonic plates move (shift) between one and fifteen centimeters per year month day minute