Amebas are single-celled organisms that need to obtain food in order to

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.

Osmosis is often viewed incorrectly as a process driven directly by differences in solute concentration across a selectively permeable membrane. what really drives osmosis? view available hint(s)osmosis is often viewed incorrectly as a process driven directly by differences in solute concentration across a selectively permeable membrane. what really drives osmosis? the first law of thermodynamicsthe difference in the height of water columns on either side of a selectively permeable membranethe difference in water concentration across a selectively permeable membranethe difference in sugar or ion concentration across a selectively permeable membrane

20. in humans, freckles are dominant to no freckles. trey has no freckles and his wife anna grace has freckles, but her dad doesn't. they want to know what percentage of their kids would look like trey. show a punnett square to support your answer.