Ncert Exercises & Solutions

50. Each of the following terms has some anatomical significance. What do these terms mean? Explain with the help of line diagrams.

(a) Plasmadesmoses/Plasmodesmata

(b) Middle lamella

These terms mean as listed

Structure	Function	Diagram
Plasmodesmata These are microscopic connecting channels between the two cells through the cell wall.	Allow communication and transport between two neighbouring cells. Plasmodesmata allow molecules to travel between plant cells through the symplastic pathway.
Middle lamella It is a layer in the cell wall mainly made of calcium pectate.	Performs the function of cementing between the two neighbouring cells.
Secondary wall It is a non-extensible layer made of hemicellulose fibres, in the cell wall of plant cells.	Provides rigidity to the cell wall in plant cell.