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.
Hi!
Both Josiah and Maleek are correct, because phylogenic trees are a type of cladograms. =)
Answer: The strongest jet streams are the polar jets. The Northern Hemisphere and the Southern Hemisphere each have a polar jet and a subtropical jet.
Explanation:
hope that helps
Answer:
Brown dwarfs are objects which are too large to be called planets and too small to be stars. They have masses that range between twice the mass of Jupiter and the lower mass limit for nuclear reactions (0.08 times the mass of our sun). ... Brown dwarfs are very dim and cool compared with stars.
Explanation:
