Question

Distinguish Between: Primary Wall and Secondary Wall

Answer 1

Hint: A plant cell wall is stacked in layers and consists of cellulose microfibrils, hemicellulose, pectin, lignin, and soluble protein. These constituents are organized into three chief layers: the primary cell wall, the middle lamella, and the secondary cell wall. The cell wall encloses the plasma membrane and offers the cell tensile control and defense.

Complete answer:

Primary wall	Secondary wall
The primary wall is arranged inner to the middle lamella.	The secondary wall is arranged inner to the primary wall.
It is produced in the young growing cell.	It is produced when the cell has stopped growing.
It is competent in extension.	Extensibility is generally absent.
It is solely layered.	The secondary wall is three or extra layered.
Hydration is 60%.	Hydration is 30-40%.
Cellulose content is relatively low.	Cellulose content is relatively high.
Cellulose microfibrils are shorter, wavy, and slackly arranged.	Cellulose microfibrils are longer, strongly arranged, straight and parallel.
The protein content is high, up to 5%.	The protein content is low, 1% or less.
Hemicellulose content is soaring, up to 50%.	Hemicellulose content is 25% of the total.
Lipid content is 5-10%.	Lipid is absent or negligible.
Supplementary chemicals like lignin are absent.	Lignin, suberin, etc. are absent.
The primary wall is slim.	The secondary wall is quite thick-walled.

Note: A cell wall is not an impassable fortress around the flimsy plant cell. There are small holes, called plasmodesmata, in the cell walls amid plant cells. The cell membranes of adjacent cells can attach through these holes. The connections allow the transport of nutrients, waste, and ions Molecules can also bypass through the spaces within the cell walls, avoiding the cells completely.