The photograph below shows some plant cells as seen under a light microscope.
the group of cells labelled z has been treated using a procedure to
more clearly visible.
what was the procedure carried out on these plant cells while they were prepared
for viewing under the microscope?

The picture from another source is attached

Staining

Explanation:

In order to make cells or certain features of a cell more visible under the microscope, scientists use specific stains. These stains bind to certain features in a cell, allowing better distinction. For example, iodine is a common stain used in plant cells, as it turns blue/black in the presence of starch, which is abundant in plant cells.

the overall balanced equation

6co2 + 6h2o > c6h12o6 + 6o2

sunlight energy

where: co2 = carbon dioxide

h2o = water

light energy is required

c6h12o6 = glucose

o2 = oxygen