What is the driving force for the movement of materials in the phloem of plants?

a) adhesion of water to phloem sieve tubes
b) root pressure
c) a difference in osmotic water potential between the source and the sink.
d) gravity
e) transpiration of water through the stomates


Ans: c) a difference in osmotic water potential between the source and the sink.

Biology & Microbiology

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An animal that is infected with a parasitic organism that can also infect humans is called a(n) ________ host.

A. transfer B. reservoir C. intermediate D. endoparasitic

Biology & Microbiology

You buy a Schlumbergera plant, also known as a Christmas Cactus, to decorate the desk where you study late into the night. It is now December, and there are no signs of flower buds forming. What is the most plausible explanation for the lack of flowers?  

A.  Flowering in this plant is controlled by both day length and temperature. The warm room and extended exposure to light are preventing flower formation. B.  The room is too cold for a cactus plant, which requires hot, desert conditions to flower. C.  Cacti are gymnosperms, not angiosperms, and thus do not form flowers. D.  As a long-day plant, the cactus requires a high light to dark ratio to flower, so it must be exposed to more sunlight. 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 flower production? 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?

Biology & Microbiology

If an injection to the mouse contains live S strain Streptococcus pneumonia, ____

a. the mouse will die b. live R strain will be detected in the mouse's blood

c. the mouse will live d. no live S strain will be detected in the mouse's blood e. the live S strain bacteria will lose their pathogenicity

Biology & Microbiology

Which protein level best matches the description "blocks on a string"?

A) tertiary B) secondary C) quaternary D) primary

Biology & Microbiology