(b) : The algal Class Rhodophyceae contains a red pigment ( r -phycocrythrin) and a blue pigment (r- phycocynin ) in the chromatphores. These pigments can utilize those wavelengths of light (blue-green region of spectrum, i.e., 480-520 nm ) that are not absorbed by chlorophyll. This enables red algae to grow at greater depths than other plants (upto 300 ft below water ) . In addition to these, chl.- a, chl.d, carotenes and xanthophylls are present. In phaeophyceae chromatophores are yellowish brown in colour possessing xanthophylls in abundance. Bacillariophyceae are called 'diatoms' due to presence of an accessory brown pigment called diatomin', other pigments are chl.- a, chl. -c (but not chl.- b ), carotenes and xanthophylls. In chlorophyceae colouring pigments are just like higher plants, i.e., Chl.- a, Chl.- b, xanthophylls and carotenes.