AP BIOLOGY

Detailed explanation-1: -The cell wall of parenchyma cells and sieve cells is mainly a primary cell wall, which contains mainly cellulose. In contrast, the cell wall of fiber cells, epidermal cells, and vessel cells is composed of the primary cell wall and the secondary cell wall; the secondary cell wall mainly contains lignin.

Detailed explanation-2: -Parenchyma makes up the chloroplast-laden mesophyll (internal layers) of leaves and the cortex (outer layers) and pith (innermost layers) of stems and roots; it also forms the soft tissues of fruits.

Detailed explanation-3: -Plant cell walls are primarily made of cellulose, which is the most abundant macromolecule on Earth. Cellulose fibers are long, linear polymers of hundreds of glucose molecules.

Detailed explanation-4: -Collenchyma tissue is composed by elongated living cells of uneven primary thick walls, which possess hemicellulose, cellulose, and pectic materials. It provides support, structure, mechanical strength, and flexibility to the petiole, leaf veins, and stem of young plants, allowing for easy bending without breakage.

Detailed explanation-5: -The plant cell wall is a dynamic network of several biopolymers and structural proteins including cellulose, pectin, hemicellulose and lignin. Cellulose is one of the main load bearing components of this complex, heterogeneous structure, and in this way, is an important regulator of cell wall growth and mechanics.