AP BIOLOGY

Detailed explanation-1: -For example, the parenchyma cells of leaves possess only a thin, primary cell wall. Collenchyma and sclerenchyma cells, on the other hand, mainly occur in the outer layers of a plant’s stems and leaves.

Detailed explanation-2: -The cell wall of parenchyma cells and sieve cells is mainly a primary cell wall, which contains mainly cellulose.

Detailed explanation-3: -Which plant cell have primary cell wall only ? Cell wall is present only in animal cells.

Detailed explanation-4: -Parenchyma cells are living cells, and may still be able to divide when they are mature. Because of this, parenchyma cells are important for regeneration and wound healing. They have thin but flexible cell walls because the secondary cell wall is usually absent.

Detailed explanation-5: -Primary cell walls are composed of polysaccharides, smaller proportions of glycoproteins and, in some specialized cell-types, various noncarbohydrate substances such as lignin, suberin, cutin, cutan or silica. Wall polysaccharides fall into three categories: pectins, hemicelluloses and cellulose.