When sleeping overnight, a person doesn't eat for many hours and blood sugar decreases. How does negative feedback work to affect this physiological value in a healthy person? A. Insulin is released to cause cells to release glucose into the bloodstream.
B. Glucagon is released to cause cells to absorb glucose from the bloodstream.
C. Glucagon is released to cause cells to release glucose into the bloodstream.
D. Insulin is released to cause cells to absorb glucose from the bloodstream.

When does the circulatory system work with the respiratory system? a. during blood cell formation b. during cellular respiration c. during intestinal digestion d. during a viral infection

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 is abiotic? a. tree sap b. insect c. sunlight d. wood table