Question

Mesophyll is differentiated into palisade and spongy parenchyma is adaptation to
a. Light intensity
b. Reduced transpiration
c. Lower water availability
d. Atmospheric humidity

Answer 1

Hint: Mesophyll cells are a type of ground tissue located inside the leaves of the plant. These cells play the most important function in photosynthesis since they comprise chlorophyll cells.

Complete answer:
> Option A is correct. High light allows the assimilating mesophyll to grow more aggressively. Under heavy light conditions, the volume of the palisade cells increased even more. The composition of the leaves as well as the light intensity applied during growth also had a significant effect on chloroplast size and number.

> Option B is incorrect. Plants control the transpiration rate by measuring the size of the stomatal apertures. Often determined by the evaporative demand of the atmosphere around the leaf, is the rate of transpiration. Reduced transpiration induces a strain of the mesophyll cells on the surface.

> Option C is incorrect. When there is less water available for the plants, dehydrated mesophyll cells release the plant hormone abscisic acid which causes the stomatal pores to close and reduce water loss during oxygen release and carbon dioxide intake.

> Option D is incorrect. The humidity around the plants saturates leaves with water vapor as it transpires. A plant cannot make water evaporate (part of the transpiration process) or draw nutrients from the soil if relative humidity levels are too high or if there is a lack of air circulation.

Additional Information:
The bulk of the leaf is produced by mesophyll tissue. It forms the leaf's green tissue and consists of chloroplasts. They are primarily palisade cells and spongy cells of two kinds. Palisade parenchyma is a thin-walled cell with a high chloroplast count, cylindrical, and responsible for photosynthesis. The ability of chloroplasts to move inside the cell is made possible by the fact that with changes in light intensity, the elongated form of palisade cells provides ample space for them to move and shift their location.

So, the correct answer is Option A.

Note: Mesophyll cells are highly differentiated cells that constitute the layer of mesophyll found in plant leaves. This layer is composed of two types of cells in the leaves of dicotyledonous plants, namely the spongy and palisade cells. Such cells also contain chloroplasts thus making the mesophyll the photosynthetic activity site.