Answer:
They have helical thickening of lignin in their walls to prevent collapse
Explanation:
the primary function of Xylem and its conducting vessels tracheids is to provide support and tranport water and minerals in plants.
Xylem vessels have layers of dead materials in the walls called LIGNIN. Lignin is a polymer; a very strong, hard materials that stop water passage through it,because it contains dead cells,
Therefore the presence of deposit of these strong impermeable, ligified walls in its walls prevent its collapse during mass flow of water of transpiration pull.
bro this is so easy,
if to animals fight, the one more adapted, prepared or psychically built will win will the weaker one lose and die, which is natural selection at its finest.
The correct answer is allele.
I hope I helped!
Answer: [D]: "oceans" .
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Note: Among the answer choices given—{aquifers, glaciers, lakes, oceans}—oceans are the saltiest (VERY salty—requiring "desalination" in order to obtain potable water.
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Answer:begins without any further replication of the chromosomes. the nuclear envelope breaks down and the spindle apparatus forms
Explanation: