Q1. Which of the following is responsible for the dark brown or reddish colour given by henna?
A Luciferin
B Melanin
C Lawsone Correct
D Hydroquinone
Explanation
Lawsone is the dye molecule in henna leaves that binds with proteins in skin, hair or nails and gives the familiar orange-red to dark brown stain. Luciferin is a light-emitting compound associated with bioluminescence, not henna colour. Melanin is the natural pigment found in skin and hair, but it is not the colouring agent released by henna. Hydroquinone is a different phenolic compound used in other chemical contexts and is not the main henna dye. The stain is therefore attributed to lawsone.