Question

When a strong wind blows, the plants bend down and then again become erect. This flexibility in plants is due to __________.
A. Sclerenchyma
B. Parenchyma
C. Collenchyma
D. Chlorenchyma

Answer 1

Here, we should know that living cells having pectin deposited cell walls can provide flexibility to plants. Cells having lignin and cellulose only can provide mechanical strength but cannot help the plant in bending.

Complete answer: When a strong wind blows, it is seen that plants bend and then regain their erect postures when the wind stops. This property of plants is very interesting to study and to know which tissue type is responsible for this character of plants let us go through each given tissue and study their respective functions.
-Sclerenchyma consists of dead cells. The cell walls are composed of lignin which is a hardening material. It provides mechanical strength to the plants. The trees stand erect due to the presence of sclerenchyma. But it has no role to play in the flexibility of plants.
-Parenchyma consists of living isodiametric cells. The cell walls are thin and composed of cellulose. Parenchyma is a permanent tissue type that means that it is specialized and has attained its final structure. The cells in parenchyma are not subjected to change. The cells have intercellular spaces between them. Some parenchyma cells do provide buoyancy to plants but no mechanical strength or flexibility.
-Collenchyma is also composed of living cells. The cell walls are made of cellulose, hemicelluloses, and pectin. They have no intercellular spaces between them. They function to provide mechanical strength and flexibility to the plants. The pectin deposition between the cells provides mechanical strength by avoiding intercellular spaces and cells are elastic that makes plants flexible.
-Chlorenchyma is a type of parenchyma tissue. It stores chloroplast and thus performs photosynthesis.
Thus, we can conclude that the right answer is option C.

Note: There are three main tissues in plants are sclerenchyma, parenchyma, and collenchyma. The collenchyma is majorly found in the cortex of stems and leaves. It is the main supporting tissue in many herbaceous plants.