IGNOU LSE 1 2015 - Describe plant cell walls and their formation.

Question

Describe plant cell walls and their formation.

23 Dec 2017

Answer :

Word Count : 822

The walls of plant cells must have sufficient tensile strength to withstand internal osmotic pressures of several times atmospheric pressure that result from the difference in solute concentration between the cell interior and external water. Plant cell walls vary from 0.1 to several µm in thickness.

Layers

Image ignouacademy-com--p-formation-94441

Molecular structure of the primary cell wall in plants.

Up to three strata or layers may be found in plant cell walls:

The middle lamella, a layer rich in pectins. This outermost layer forms the interface between adjacent plant cells and glues them together.

The primary cell wall, generally a thin, flexible and extensible layer formed while the cell is growing.

The secondary cell wall, a thick layer formed inside the primary cell wall after the cell is fully grown. It is not found in all cell types. Some cells, such as the conducting cells in xylem, possess a secondary wall containing lignin, which strengthens and waterproofs the wall.

Composition

In the primary (growing) plant cell wall, the major carbohydrates are cellulose, hemicellulose and pectin. The cellulose microfibrils are linked via hemicellulosic tethers to form the cellulose-hemicellulose network, which is embedded in the pectin matrix. The

____ ______ _____ _________ ________ _____ ___ ____ ________ ___ _________ _________.
____ ___ ______ _____ ________ _________ _____ ______ _____ __________ _______ _______.
________ _______ ___ _________ ______ __________ ___ ____ _____.
_____ ___ ______ ____ _______.
_________ _____ _________ ____ ______ __________ ________ ___ _________.
____ ____ ______ _____ __________ ______ _________ ______.
_________ ______ _____ __________ _______ __________ ____ ________ _________ __________ _______ _______.
______ _____ ____ _____ _______ ___ _________.
_______ _____ ________ ______ _______ ________ ________.
_____ ___ _________ ____ ________ ___ ___ ____ __________ __________ ____.
___ ________ _____ ______ ___ ___ _____.
_________ _____ ________ _____ ______ _____ _____ ____ ____ __________ _______ _________.
_______ ___ __________ _____ ____ _________ _____ _______ _______.
___ ____ ________ _______ _______ _________ ________ _____ _________ ________ __________ ______.
_____ _______ _______ ___ _____ _____ ________.
________ ___ _____ ________ _______ ____ _________.
_______ _____ __________ ___ ___ ___ _______ ___ __________.
_____ ______ ___ ________ __________ _____ ___ ____ _______ ____ ______ _______.
_____ ______ _________ ___ _____.
________ ______ ___ ____ _______ _________ ______ _____ ____ _______ ______.
________ ______ _________ _______ ______ ________ ________ ___.
_____ __________ ______ _____ ___ ____ _________ ______ __________.
_______ _________ ______ _____ _________ ______ _____ __________ _____ ____.
______ ________ _______ __________ ____ _____ ________ _______.
____ _____ ____ _____ _______ _________ _____ _________ _______ __________ _______.
_____ _________ __________ __________ ________ _________ ______ ________ _____.
____ _________ ___ ___ ___ _________ _______ __________ _______ ________ _____ ______.
_________ ___ _________ _____ __________ _________ _________ _______ ____ ______ _______.
_________ _______ ______ ___ _________ ___.
_________ _____ _______ _________ _________ _______ _____.
___ _________ __________ __________ ____ _____.
____ ____ _____ ______ ______ ________ ____ ________.
________ _________ ______ ____ ___ ___ ____ _______ ______.
_______ _______ ______ __________ ____ ____ ___ ___ __________.
_________ _________ __________ ___ _______ ________ _______ ______ _____ ______ ______ _______.
__________ _______ ____ ___ __________ ____ ________ _____ _______.
_________ ____ ____ _________ _______ __________ __________ ________.
_________ ___ ____ ___ ______ _________ _______ _______.
_______ _____ _________ ___ ____ ____ __________ ________ _____ _____ __________ _________.
__________ __________ ___ _________ ______ _____.
______ ______ _______ _____ _____ _________ ______ ________ ____.
_______ _______ _________ ________ ______ ______ __________.
_________ _____ ________ ___ _____ _______ ___ _____ ________ _______.
______ ___ _________ ______ ________ _______ _________ ____ ____ _____ ____ ______.
__________ ________ ______ ______ _______ ______.
____ _____ __________ __________ ____ __________ _________.
___ _______ _______ ___ _____ __________ ___ ________.
_______ __________ ________ _____ _____ _____ _____ _______ __________ ______ __________ ___.
___ ______ _________ ________ ____ ____ _________ ___ ___.
_______ __________ ___ __________ _________ __________.
__________ ___ ___ _______ __________ ____ _______ ___.
_____ __________ _________ _______ _______ ___ ________ ______ ___ ____ ________.
______ ____ ______ ______ _____ ____ _________ _________ ___ ___ ____ _______.
______ ___ ____ ______ _________ ______ ________.
______ _______ ____ __________ ______ _________ _________ ________ _________.
__________ ______ ________ ____ ______ _______ ________ ______.
_________ _______ ______ _________ _____ ____ ____ ________.
____ _____ ______ _______ __________ _________ ______ _______ _____.
________ ______ ___ __________ __________.
________ ___ _________ _____ ___ ___.
________ ________ ___ ________ _______ ___ __________ ______ _______ ______.
_________ _________ _________ ___ _______ _____ ____ ______ ________ __________ ______ ________.
______ _________ _____ __________ _______.
_________ _______ ___ ________ ________ ________ ______.
________ _____ ____ ______ __________ ____ ___ _________ _________ __________.
_____ __________ ______ __________ ______.
_______ ________ _________ __________ _____ ________.
__________ _____ ______ __________ _____ ______ ________ ___ _________ ________.
________ ________ ______ ____ _____ __________ ________.
_______ ______ _______ _____ _________ ____ ____ ___ _____.
________ __________ _____ ____ _______ _____ __________ ________ ____ _________ ______ ___.
_______ ________.

IGNOU ACADEMY

Your IGNOU journey, made easier.

Solved Assignments
Study Notes
Guess Papers
Question Papers

Call Us WhatsApp

STUDY • PREPARE • SUCCEED

Skip in 10

IGNOU Solved Assignments Assignments Ignou Projects Project Previous Year Solved Exam Papers Notes Notes Sample Question Papers Sample Question Papers