A researcher is interested in the effect of fertilizer on the numbers of flowers produced. She sets up an experiment with 4 groups of identical rose bushes. Group 1 receives 1 ounce of fertilizer, Group 2 receives 2 ounces, Group 3 receives 3 ounces and Group 4 receives no fertlizer. The plants receive the same amount of water, sunlight and humidity. She counts the number of flowers on each plant at the end of one month. What is the independent variable in the study? a. number of flowers
b. height of plant
c. amount of water
d. amount of fertilizer

Which of the following describes a negative feedback loop? when the heart rate is too high, the body sends hormones that continually increase the heart rate higher. when a pregnant woman is in labor, the body sends hormones that increase the intensity of contractions, which then increases the secretion of the same hormones. when blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows. when a person is jogging, the body sends hormones that continually decrease the rate of oxygen supply to the legs.

The chemical form of energy that is useable by the cell to do work

What is the main difference between the central nervous system (cns) and the peripheral nervous system (pns)? .the cns involves the brain and spinal cord, and the pns involves the body nerves. the cns involves the body nerves, and the pns involves the brain and spinal cord. the cns involves sensory neurons, and the pns involves motor neurons. the cns involves motor neurons, and the pns involves sensory neurons.