Green plants do not necessarily have chloroplasts. Plants are autotrophs that can carry out photosynthesis, transform inorganic substances into organic substances and live independently. Photosynthesis requires photosynthetic pigments (most plants rely on chlorophyll for photosynthesis, but some do not, such as cyanobacteria, which rely on phycocyanin for photosynthesis without chloroplasts), so most of the plants we see are green, and plants that can carry out photosynthesis are biologically called green plants. Green plants also contain some autotrophic bacteria (bacteria only have ribosomes as organelles)