Chloroplasts (here colored yellow) are organelles in cells of plants and algae that capture energy from sunlight and convert it to chemical energy by photosynthesis. We are dependent on photosynthesis because it is responsible for most of the world's primary productivity, and also because fossil fuels are mostly from remains of prehistoric plants. A typical plant cell contains about 10 to 100 chloroplasts. Chloroplasts are descended from early in evolutionary history when a eukaryotic cell incorporated photosynthetic cyanobacteria. Chloroplasts contain their own DNA that descends from the cyanobacterial ancestor.
2015 has been designated as the International Year of Light
Different color stains were used to see various structures in the plant cells: nuclei (colored red/cyan/white), cell walls (colored green), and chloroplasts (colored yellow). The stained plants were sectioned and viewed using a confocal microscope.
Fernan Federici, PhD, Departamento de Genética Molecular y Microbiologia, Universidad Católica de Chile, Chile and Jim Haseloff, PhD, Department of Plant Sciences, University of Cambridge, UK