All the following are true of companion cells EXCEPT that they
A) cooperate with sieve-tube elements in conducting sugar-rich solutions.
B) are connected to sieve-tube elements via plasmodesmata.
C) supply materials to repair the plasma membrane of sieve-tube elements.
D) provide proteins and ATP to sieve-tube elements.
E) fuse together to form the sieve plates of sieve-tube elements.
E
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How would the presence of endospores in Louis Pasteur's nutrient solutions have affected his conclusions about spontaneous generation?
What will be an ideal response?
A friend tells you the following story. "My aunt just received a heart transplant. Her doctors warned us that her body might reject the tissue. I just can't understand how that could happen as human hearts are made of the same tissues, aren't they?" How do you respond?
A. "Yes, all human hearts are made of cardiac muscles." B. "Yes, all human hearts are made of cardiac muscles, except some humans have different tissues inside their hearts and this could lead to a tissue rejection by the recipient." C. "Yes, all human hearts are made of cardiac muscles. As far as the rejection of tissues goes, your aunt might have different antibodies than did the donor, which could lead to a rejection." D. "Yes, all human hearts are made of cardiac muscles. However, your aunt might have been given some type of drug during the transplant operation that might cause tissue rejection. You can never be too careful in a hospital, you know." E. "Yes, all human hearts are made of cardiac muscles. As far as the rejection issue, everyone has different MHC proteins on their tissues. Your aunt's immune system recognizes the ‘self' tissues but can cause tissue rejection because of the ‘nonself' tissue in her body having different MHC proteins." Clarify Question What is the key concept addressed by the question? What type of thinking is required? Gather Content What do you already know about tissues and transplants? What other information is related to the question? Choose Answer Given what you now know, what information is most likely to produce the correct answer? Reflect on Process Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
Cells obtained from a Triplo-X woman would contain ________ Barr bodies
A) 0 B) 1 C) 2 D) 3 E) 4
Considering that leaf stoma have the conflicting functions of allowing gaseous carbon dioxide into the leaf, yet preserving the plant's supply of water, which of the following is (are) reasonable?
A. Corn, oats, rice, and wheat-all monocots-have relative upright blades with sunlight hitting both sides and would have stoma distributed evenly on both sides. B. Tree leaves that orient flat and present the top side to the sun would have most of their stoma on the bottom of the leaf. C. A submerged-water plant would have no stoma. D. All of the choices are reasonable. E. None of the choices are reasonable, since stoma are found uniformly on all type of leaves.