Practice question

Kingdom Plantae or Viridiplantae is monophyletic assemblage consisting of green algae plus land plants descended from single common ancestor that acquired primary endosymbiotic chloroplast from cyanobacterium roughly 1.6 billion years ago. Monophyly strongly supported by shared synapomorphies: presence of chlorophyll a and b in chloroplasts with stacked thylakoids forming grana, cellulose cell walls synthesized by rosettes, starch storage inside plastid, peroxisome-based photorespiration and charophycean-type open mitosis. Traits like seeds, vascular tissue, flowers arose independently later within kingdom after divergence. Single ancestry distinguishes from polyphyletic algae.