17,000 just because you lost it does not mean you did not make it
Oort cloud: a spherical region that surrounds the solar system, that extends from the kuiper belt to almost halfway to the nearest star, and that contains billions of comets
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.
The sender is.....Nucleotides. DNA is made of chemical building blocks called nucleotides.
