Why are seaweeds put in the protist kingdom?

Seaweeds are classified in the protist kingdom because they are primarily simple, multicellular organisms that do not fit into the categories of plants, animals, or fungi. They possess characteristics typical of protists, such as being primarily aquatic and having photosynthetic capabilities due to the presence of chlorophyll. Additionally, their cellular structure and reproductive methods align more closely with protists than with higher plants. This classification reflects their evolutionary history and the diversity found within the protist kingdom.