The movement of phloem sap is best described from the ____ to the ____
a. shoot system; root system
b. sinks; sources
c. root system; shoot system
d. sources; sinks
e. shoot system; sinks
ANSWER: d
You might also like to view...
You are having lunch with an elderly friend when suddenly he begins to experience chest pain and tightness. He reaches into his pocket, gets out one of his nitroglycerin tablets and quickly takes it. After the episode passes, your friend asks you how the nitroglycerin helps his angina. You explain that nitroglycerin gets converted by cells to nitric oxide (NO) causing the smooth muscle cells of the blood vessel to relax and increase blood flow to the heart. He pushes you for a more detailed explanation, so you explain further that:
A. NO activates a protein kinase which catalyzes the synthesis of cGMP, which acts as an intracellular messenger in a pathway leading to smooth muscle relaxation. B. NO activates guanylyl cyclase, which catalyzes the synthesis of cGMP, which acts as an intracellular messenger in a pathway leading to smooth muscle relaxation. C. NO inhibits guanylyl cyclase, which allows the build up of cGMP, which acts as an intracellular messenger in a pathway leading to smooth muscle relaxation. D. NO activates cGMP, which catalyzes the synthesis of guanylyl cyclase, which acts as an intracellular messenger in a pathway leading to smooth muscle relaxation.
Together, follicle-stimulating hormone and luteinizing hormone are
A. metabolic hormones. B. growth hormones. C. adrenocorticotropic hormones. D. gonadotropic hormones.
All of the following statements about catalysts are true EXCEPT
A) catalysts increase the reaction rate. B) catalysts are not permanently altered during reaction. C) catalysts increase activation energy requirements. D) biological catalysts are specific enzymes. E) catalysts can be used repeatedly.
A scientist performs an experiment in which they create an artificial cell with a selectively permeable membrane through which only water can pass. They inject a 5 M solution of glucose into the cell and then place the cell into a beaker containing 10 M glucose. What effect do you expect to observe?
A. water moves out of the cell B. glucose moves into the cell C. glucose moves out of the cell D. water moves into the cell E. no net change in cell weight