What do x and y chromosomes affect? a. the shape of a person's thumb. b. how many parents a person has. c. whether someone is a female or male. d. whether earlobes are attached.

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.

When energy is used, atp molecules convert to adp molecules. this process is called

The earth formed roughly 4.5 billion years ago, yet evidence of life dates back to about 3.5 billion years ago. which one is not a possible hypothesis of how life on earth arose?