Why do deciduous trees lose their leaves? a. deciduous trees lose their leaves to prevent oxygen loss. b. deciduous trees lose their leaves to defend from predators. c. deciduous trees lose their leaves to prevent nutrient and water loss. d. deciduous trees die in winter.

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.

How can you tell the difference between rough er from smooth er?

The function of the excretory system is to control homeostasis and