The answer is C. sooooooooooooooooooooooooooooooooooo i whve to take up space
The answer is <span>2 can be made by the animal's body from other substances.
Both essential and nonessential amino acids have essential roles in the organism. Nonessential amino acids got their name because they are not an essential part of the diet. The main difference between these two groups of amino acid is that essential amino acids cannot be made by the animal's body and must be ingested in the diet unlike the nonessential amino acid which can be made by the animal's body.</span>
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.
What he did was say that evolution happened that over time the birds seemed to be changing
