Chloroplasts are green organelles found in plants and green algae. They contain chlorophyll a and b pigments for photosynthesis. Chloroplasts are 1-2 μm thick and 5-7 μm in diameter
Cells are the basic structural and functional units of living organisms. Organelles are cellular components that perform specific functions. Organelles are classified based on their membrane presence
Stomata are microscopic pores on plant epidermis surrounded by guard cells. Guard cells control stomatal opening and closing in response to environmental conditions. Stomata facilitate gas exchange and water movement between plant and atmosphere. Transpiration supplies water and minerals to entire plant system
Pyrenoids are sub-cellular compartments found in chloroplasts of algae and hornworts. They contain RuBisCO enzyme and form a CO2-rich environment around it. Pyrenoids are not delineated by protein shells but often have starch sheaths
Unicellular organisms consist of a single cell, unlike multicellular ones. Most prokaryotes are unicellular, including bacteria and archaea. Unicellular organisms are thought to be the oldest form of life. Early protocells emerged 3.5-4.1 billion years ago
Euglena is a genus of single-celled flagellate eukaryotes found in freshwater and salt water. Species can bloom in ponds, creating green (E. viridis) or red (E. sanguinea) colors. Euglena gracilis serves as a model organism in laboratories