Which hypothesis is testable?
plants that are grown by using brand a fertilizer taste best.
plants that have flowers look prettier than plants that do not have flowers.
plants will eventually die off if global warming trends continue.
plants make more sugar on sunny days than on cloudy days

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.

Depending on the organism the number of in a cell may change

What would happen if the krill were removed from the food web