Archaeplastida

Archaeplastida is a major taxonomic group primarily composed of photosynthetic algae. These organisms evolved from a heterotrophic ancestor that acquired a plastid through primary endosymbiosis with a cyanobacterium. This group includes the glaucophytes, red algae, and green algae, with green algae being the lineage that gave rise to land plants. Plastids in Archaeplastida are surrounded by two membranes. While most members are photosynthetic, some have secondarily evolved heterotrophic feeding methods. The classification of algae within Archaeplastida is complex and has evolved with advances in microscopy and molecular biology.1234