Can coal ever be truly a clean-burning fuel?

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.

In a leaf, dermal tissue a) stores food b) stores carbon dioxide c) releases oxygen into the air d) transports water from the roots

The means by which a cell transports large molecules out of the cell is called