You are studying planar cell polarity in the developing chick epidermis (feathers all go in the same direction). You hypothesize that this is caused by planar cell polarity established near the head of the embryo. To test this, you take cells expressing exclusively Frizzled and Disheveled in the head region of a chick embryo and transplant them to the middle region of the same embryo. Predict the feather direction in the chick if your hypothesis is right and if it is wrong. Justify your answer.

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.

Which of these transport mechanisms moves glucose from the blood into a cell? active transport diffusion facilitated diffusion osmosis

What causes eclipses? check all that apply. earth's rotation on its axis moon's shadow covering the sun earth's shadow covering the moon earth's orbit and moon's orbit occasionally aligning the moon and sun's gravity pulling in the same direction