Q.The accessory pigments carotene (orange) and xanthophyll (yellow), which broaden the range of light a leaf can capture, both belong to the pigment class known as the:

Carotenoids -- carotene (orange, $C_{40}H_{56}$) and xanthophyll (yellow, $C_{40}H_{56}O_2$) -- are accessory pigments that broaden the range of usable light and protect chlorophyll from photo-oxidative damage under excess light. The absorption spectrum of a pigment (measured on an isolated extract, showing chlorophyll's two peaks in blue-violet and red, with a trough in green -- why leaves look green) is distinguished from the action spectrum (the actual photosynthetic rate of a living leaf at each wavelength, as Engelmann effectively measured via bacterial clustering). The close over …