MCQ IN MEDICINE

Detailed explanation-1: -Lignin is a waterproofing and strengthening cell wall polymer that is essential to the functioning of certain plant cells, particularly those involved in water transport.

Detailed explanation-2: -The polysaccharide components of plant cell walls are highly hydrophilic and thus permeable to water, whereas lignin is more hydrophobic. The crosslinking of polysaccharides by lignin is an obstacle for water absorption to the cell wall.

Detailed explanation-3: -The lignin adds compressive strength and stiffness to the plant cell wall and is believed to have played a role in the evolution of terrestrial plants by helping them withstand the compressive forces of gravity. Lignin also waterproofs the cell wall, facilitating the upward transport of water in xylem tissues.