Question

Leaves have air spaces to allow for carbon dioxide and oxygen to move into and out of cells for photosynthesis, which causes water to evaporate and creates greater tension on the mesophyll cells. How do xylem vessels and tracheids prevent collapse in these conditions?

a. Photosynthesis is reversed at times to bring together oxygen and hydrogen ions
b. Metabolic dehydration reactions provide excess water to replace it
c. The turgor pressure of surrounding cells pushes the mesophyll cells into shape
d. Lignin keeps water flowing through the cells
e. Rings maintain their tubular shape

Answer 1

They have helical thickening of lignin in their walls to prevent collapse

Step-by-step 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.