In plants the new born leaves look pink in colour but later on they turn green. Let us study the reason behind it. It is known to all that the colour of a substance depends on the absorption and reflection of different colours of light. There are some substances in the leaves
which give colour to them, like presence of chlorophyll in plants make them green whereas the presence of carotene in plants make them yellow. The leaves of some plants look yellowish green because they have both carotene and chlorophyll in them. In some plants the new born leaves contain only one substance called anthocyanin, which gives red or pink colour to the tender leaves. Later on, the carotene and chlorophyll are formed in these leaves and turn them green. The arrangement of chlorophyll molecules in leaves is such that when the sunlight falls on the leaves, they reflect the green colour and absorb the rest of the colours. We can see this reflected green colour. In the presence of sunlight plants make their own food with the help of chlorophyll. This process of making food is called photosynthesis. Plants cannot make food without chlorophyll e.g. fungi. They depend on other living beings for food and are called parasites. Thus chlorophyll is essential for plants.