Chloroplast. Artwork of a chloroplast in close-up,in a sectioned plant cell. Chloroplasts are one of the features that distinguish a plant cell from an animal cell. They contain chlorophyll,a green pigment that is needed to use energy from sunlight during photosynthesis,when carbohydrates are made from carbon dioxide and water. It contains stacks (circular) of flattened membranes,called grana,that contain the chlorophyll. It is thought that,during cell evolution,chloroplasts originated as once-independent micro-organisms. The cell wall (yellow),the nucleus (pink),and two peroxisomes (blue spheres) are also seen. Peroxisomes contain enzymes that help oxidise harmful materials |