NEET BIOLOGY

Detailed explanation-1: -The major compounds of the wood cell walls are cellulose, hemicelluloses and lignin. Together, these polymers form so-called lignocellulose complex that provides structural rigidity and protects the wood cells from microbial attack (Mäkelä et al., 2014).

Detailed explanation-2: -The cell wall surrounds the plasma membrane of plant cells and provides tensile strength and protection against mechanical and osmotic stress. It also allows cells to develop turgor pressure, which is the pressure of the cell contents against the cell wall.

Detailed explanation-3: -In the xylem vessels, water molecules are strongly attracted to each other and exhibit a “stickiness” called cohesion that is due to the formation of hydrogen bonds between different water molecules. The “stickiness” between water molecules and the xylem vessel walls is called adhesion.

Detailed explanation-4: -Water molecules are polar and can form a type of intermolecular association called a hydrogen bond. This cohesive property causes water molecules to be dragged up the xylem towards the leaves in a continuous stream.