Cell wall is the outermost layer in the eukaryotic cells (absent in animals). It is a non -living and rigid layer. The main function is to protect the cells and also to give shape to the cells. It also prevents entry of unimportant substances. Young cells contain three layers: Primary wall, middle lamella and Secondary wall. Primary wall is responsible for growth and hence it is not seen in adult cells. Middle lamella is seen in all types of cells. This contains calcium pectate which helps to stick to the neighbouring cells. Plasmodesmata connects the middle lamella and cytoplasm of neighbouring cells.