Two subgroups of a population separated by a river are rejoined when a drought causes the river to run dry. Assuming that speciation has not yet
occurred, what is true about the two subgroups?
A. The likelihood that speciation will be completed will decrease.
B. New traits that resulted from mutation will not flow between the
subgroups.
C. The two subgroups will still be reproductively isolated and unable
to mate.
D. Speciation will speed up since there will be more competition
between the subgroups.

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.