Question

Collenchyma is characterized by:
A. Isodiametric cells with uniform thickenings
B. Isodiametric cells with uneven thickenings
C. Elongated cells with thickenings at selected places
D. Elongated cells with uniform thickenings

Answer 1

Hint: Simple permanent tissues are present inside the plants. These tissues are made up of only one type of cell which come together to perform a particular function. Collenchyma is one such simple permanent tissue, which is made up of living plant cells.

Complete answer:
To solve the question, we must be well aware of the plant tissues. Tissue is a group of similar or dissimilar cells that come together to perform similar functions. These cells have the same origin and almost the same structure.
In plant, tissues may be of two types:
>Meristematic Tissue
>Permanent Tissue

Meristematic tissues are those tissues which continuously multiply while permanent tissue are those which have lost their ability to multiply and are now specialized to perform specific functions.
The permanent tissue is of three types:
>Parenchyma
>Collenchyma
>Sclerenchyma

Collenchymatous cells have thick walls. These thickenings are usually made up of cellulose or pectin.
Angular collenchymatous cells have thickenings present at different angles. Lamellar collenchymatous cells have plate-like thickening and in tubular collenchyma intercellular spaces are present.

Therefore the correct answer to the question is that the collenchymatous cells are isodiametric with uneven thickenings.

Note: It must be noted here that the main function of the collenchyma is to provide mechanical support to the plant. Sometimes even chloroplast is present in them, and then these cells also perform photosynthesis.