When you heat a test tube, what should you do? (select all that apply.)
a. put a stopper in the top of the tube to prevent fumes from escaping.
b. point the tube opening away from your face or the faces of others.
c. look inside the tube often to observe results.
d. pick the tube up with a test tube holder or protected hands.

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.

What molecule does hemoglobin decay into over time

Body temperature is tightly regulated in mammals for example when external temperatures drop too much the body of a mammal response by in order to it's core temperature.