Question

What do the pits in the xylem mean? Is it similar to the perforations on the common walls?

Answer 1

Hint: Xylem is a conductive tissue in a plant that helps in the movement of water and minerals across the plant. They also provide mechanical support due to the presence of thick lignified cell walls.

Complete answer:
Pits are the thin segment of the cell wall through which the adjacent cells are able to transfer or exchange fluid. These act as characteristic features of cell walls that constitute the secondary layer. Mostly each of these pits consist of a complementary pit which is present opposite to it in the neighboring cell and these complementary pits are referred to as “pit pairs”.
Pits possess three parts – the pit chamber, the pit aperture and the pit membrane. The pit chamber is that hollow segment where the secondary layers of the cell wall are absent. The opening at either side of the pit chamber is the pit aperture. The pit membrane is the primary cell wall or middle lamella between adjacent cell walls in the middle of the pit chamber. In the secondary cell wall of the xylem tissue, one can notice the presence of minute openings called the pits. The main function of these pits is to transport water and minerals between the adjacent cells.
From the above discussion, we understand the concept of pits and that pits are not similar to the perforations on the common walls.

Note-
Though pits are simple and complementary, a few variations can be formed in the form of simple pit, bordered pit, half bordered pit, blind pit and compound pit. These pits vary in sizes and structure and the number they are available in.