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.

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Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a.one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b.one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c.one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.