Question

Why some algae are considered to be in kingdom protista?

Answer 1

Algae can be placed in the kingdom protista Idepends whether it is unicellular or multicellular, prokaryotic or eukaryotic.

If its unicellular and eukaryotic, then despite being photosynthetic, its placed in kingdom protista. Eg euglena, diatoms , chlamydomonas etc

If its multicellular and eukaryotic , then its placed in plantae, eg Members of Chlorophyceae( green algae) , Phaeophyceae( brown algae) and Rhodophyceae ( red algae)

Some prokaryotic algae ( BGA) are placed in monera