Question

the leaves of Marigold plant appears green but the flower at very low will invite sunlight give reason

Answer 1

A leaf appears green in daylight because it absorbs all wavelengths of visible light spectrum except the green colour, and therefore it appears green as they reflect it. But when solely red light is given to the leaf, it will absorb the red light and therefore appears as black. As we know when all the wavelengths of the spectrum are absorbed, the subjected object appears black; and if they appear white, that means the object reflects the incident light.