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 answer is A. Rabbits eat grass. The snakes eat the rabbits and the hawks eat the snakes. So if rabbits died off, so would the snakes, and the hawks. Because both of their food sources would deplete. And grass would flourish.
The best option is D. Based on scientific evidence about algal bloom, it would be best to evacuate all humans from the area around the lake. Algal bloom is caused by excess nutrients in the lake. This occurrence is linked to the death of fishes, plants, mammals and birds. Also. it has been said to cause human illnesses. Thus, to avoid this, it would be best to stay away from the lake with algal bloom.
Answer:
The answer is C) osteopenic
