Chlorophyceae

Chlorophyceae is a class of green algae within the division Chlorophyta, comprising between 9,000 and 12,000 species. These algae share key characteristics with higher plants, including the presence of chlorophylls a and b, and carotene pigments. Their cells typically contain a central vacuole, pigments within plastids, and a cell wall made of cellulose and pectin. Food is stored as starch in structures called pyrenoids.1

Green algae exhibit diverse forms, including single-celled, colonial, filamentous, and tubular shapes. They reproduce both asexually through cell division, spores, or fragmentation, and sexually via gametes with flagella. Most green algae inhabit freshwater environments, but terrestrial and marine species also exist. They play a crucial role as food and oxygen sources for aquatic life and are considered important in the evolutionary study of plants, with some species like Chlamydomonas thought to resemble the ancestral form of land plants.123