The chlorosis is the yellowing of the leaves it may be symptoms of some plant disease or infection. This yellowing may be also due to the ageing, deficiency of nutrients, infection of disease, absence of light etc. When these causes are not treated effectively it will result in the death of the plant.
Whereas the etiolation is the condition of the plants when they are exposed to darkness. Under the dark condition the stem of the plant elongates well, the leaves become stunted in growth where yellowing the leaves also occurs due to less manufacturing of the chlorophyll. This condition can be treated when the plant is exposed to sufficient light intensity.
