How biologist think that ancient green algae were ancestor?

Biologists believe that ancient green algae are ancestors of land plants due to their shared cellular structures, photosynthetic pigments, and genetic similarities. Both groups utilize chlorophyll a and b for photosynthesis and possess similar cell wall compositions. Fossil evidence and molecular data suggest that land plants evolved from a specific lineage of green algae, supporting the idea of a common ancestry. This evolutionary relationship highlights the transition from aquatic to terrestrial life.