Question

Do animal cells have a cell wall?

Answer 1

Hint: The cell wall covers the outermost layer of the cell. It is present on top of the cell membrane. It is tough, flexible and rigid. It provides cell protection and structural support. It separates the interior content of the cell from the harsh exterior environment. The composition of the cell wall varies from cell to cell. They are mostly made up of polysaccharides, polymers, glycoproteins, peptidoglycan and silica.

Complete explanation:
Animal cells do not possess cell walls. Cell walls are present only in prokaryotes, algae, fungi and plants. The cell wall of plants is made up of polysaccharides such as cellulose, hemicelluloses and pectin. Algal cell wall is made up of polysaccharides and glycoprotein such as carrageenan and agar. Fungi cell walls contain chitin and prokaryotes cell walls are made up of peptidoglycans.
The Cell wall is hard and rigid offering the cell protection against mechanical stress. It also gives the cell a proper shape. Cell wall is also selectively permeable in nature. It prevents the entry of large molecules that may be toxic to the cell. It helps in the creation of stable osmotic environments by preventing osmotic lysis and retaining water. The composition and properties of the cell wall may change during the cell cycle and growth.
Animal cells only contain cell membranes. It is present as a thin semi permeable layer surrounding the cell and made up of protein and fats. It protects the cell from harsh external surroundings.

Note:
The plant cell wall is usually arranged in three layers called primary cell wall, middle lamella and secondary cell wall. The primary cell wall is present closest to the inside of the cell. Its main role is to allow the wall to stretch for the purpose of growth. Middle lamella is the outermost layer of the cell and it acts as an interface between two neighbouring cells. It is primarily made up of pectin, lignin and proteins. The secondary cell wall is present within the primary cell wall. It is the thickest layer and provides shape and permeability to the cells.