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

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.