xylem vessels造句

例句与造句

1. The xylem vessels at the base of a tree can't grow beyond a certain diameter, he says, because bubbles are more likely to form in big tubes.
2. She has shown that membranes linking a tree's xylem vessels may swell or shrink in response to the concentration of charged molecules, called ions, dissolved in the water of the xylem.
3. Xylem cells are specialised for conduction of water, and first appeared in plants during their transition to land in the Silurian period more than 425 million years ago ( see " xylem vessels.
4. Physical characteristics, such as diameter and density of xylem vessels, is due to the plant s genetic makeup, but also many environmental factors as well ( for this experiment it was rainfall ).
5. In summary, there are a couple of factors that limit the ability of a tree to pull water from the soil to the top . 1 ) The strength of xylem vessels to with stand the negative pressure creating by " sucking " the water up . 2 ) the amount of force available from transpiration to pull water to the top of a tree.
6. It's difficult to find xylem vessels in a sentence. 用xylem vessels造句挺难的
7. It would seem to me, the larger the tree, the stronger the xylem vessels would be, the stronger the force available from transpiration etc . . . The only answer I can think of as to why trees don't continue growing forever is that the eventually die, which leads me back to my above question concerning whether or not trees have natural lifespans.
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