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.
Well matter is basically any substance that has mass and takes up space. Example, you have a ball, or a table, or anything really. That is mass. But anything that doesn't take up space or has mass isn't matter. So, anything that doesn't have a mass or take up space is not matter. Hope this helped you understand. :D
The difficulty with this answer, lies in the fact that not all of land and ocean biomes have been completely explored. The ocean is vast, covering approximately 70% of the Earth's surface, with literally vertical miles or kilometers of depth, and with some areas with sparse to no biodiversity. The same can be said about certain areas of large deserts with very low levels of biodversity, void of life, like vast deserts of the Sahara or Gobi. But, the Amazon rain forest contains still unknown species of plant and animal life, just like the ocean. Because of its vastness, intellectually, I would say the ocean contains more biodiversity, but the answer is scientifically, as of now, yet to be proven one way or the other.
Answer:
c let me know if i am wrong
Explanation:
Answer:
Walls are thin.
Inner surface is moist.
Tissues are filled with blood vessels.
Exposed to air
Explanation: