Question

Why the tomatoes are in red colour and also name the alkane that is responsible for red colour

Answer 1

As the tomato ripens, its colour starts to change from green to yellow and then eventually to red. This is due to the breakdown of chlorophyll, which in turn synthesises a red carotenoid (another pigment group), lycopene. When ripe, the carotenoid can easily be seen as the dominant colour of the tomato, ie red.