Practice question

Photosynthetic pigment composition provides important chemotaxonomic marker clarifying green plant evolution. Land plants and charophyte green algae contain chlorophyll a as primary reaction center pigment plus accessory chlorophyll b broadening absorption peaks in blue and red spectrum, with carotenoids beta-carotene, lutein and other xanthophylls for photoprotection. This specific combination housed in chloroplasts with grana stacks distinguishes Viridiplantae from Rhodophyta possessing chlorophyll a and phycobilins, Phaeophyta and diatoms with chlorophyll a and c plus fucoxanthin. Retention of chlorophyll a plus b supports close kinship.