Which of the following statements accurately describe variation in human skin color? Data support a correlation between UV intensity and skin color variation.

Human skin color variation is mostly determined by the types and amounts of melanin present in the skin.

Variations in human skin color can be quantified, or measured.

On average, the skin color if indigenous peoples around the world correlates with UV intensity in their environments.

All of these are accurate.

Which of these statements best describes the st. lawrence seaway? the st. lawrence seaway connects the st. lawrence river with the arctic ocean. the st. lawrence seaway provides an important trading route between the u. s. and mexico. the st. lawrence seaway provides an important trading route for the u. s, but has little value for canada. the st. lawrence seaway connects the great lakes, the st. lawrence river, and the atlantic ocean.

Match the following terms describing electrical events with the correct phases of the cardiac cycle. the ventricular muscle cells depolarize at the start of this phase. during this phase, na+ entry through the funny channels causes the pacemaker potential of sa nodal cells to gradually become less negative until it reaches threshold. the ventricular muscle cells repolarize right before this phase. the cytosolic concentration of calcium in the contractile cells of the ventricle is highest during this phase. a. isovolumetric relaxation b. ventricular ejection c. isovolumetric contraction d. ventricular filling

Building glycogen from glucose molecules is an example of what