Category: Science


Chlorophyll is a substance found in chloroplasts, found in the cells

of leaves. They are used to produce glucose which is used as plant

food and growing materials (e.g. cellulose).A leaf which is exposed to

plenty of light will have sufficient amounts of food and will not need

an excessive amount of chlorophyll. This enables the leaf to have a

small surface area. It is also necessary for leaves in areas of high

light intensity, and thus high temperature, to have small leaves to

reduce the amount of transpiration. The heat will cause water to

evaporate a lot faster.

Leaves in shaded areas will need a large surface area full of

chlorophyll to collect as much sun light as possible; essential for

survival. These leaves will also have no threat of excessive

transpiration because the temperature in the shaded area will be lower

and the humidity probably higher.

Transpiration is the removal (evaporation) of water from a plant

through the stomata in the leaves; this water is removed in a cycle

due to the active uptake from the roots. Transpiration involves

osmosis; which is the diffusion of water from a high concentration to

a lower concentration through a partially permeable membrane, until

both the concentrations are equally saturated.

All these factors i.e. transpiration and photosynthesis, come together

to confirm my hypothesis.

To support my hypothesis further, I did a pilot study in a meadow in

which I studied the population of certain plant species in areas of

different light intensities. I learned that different plants need

different environmental factors to grow well. The leaves in the shade

were larger than those in the open field.