What action will slow down the rate of a reaction?
a. raising the temperature of the reactants
b. decreasing surface area of a solid reactant
c. increasing the concentration of the reactants
d. adding a catalyst to the reaction

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.

Wich level of organization includes all the other levels or organizations

What is responsible for the uneven heating between the poles and the equator on any given day