... stuff. So here we go. Substance is anything that occupies space and has mass. Substances are diverse: air, water, rock and wood are all substances. Most substances can be broken down into other substances by chemical means. Any substance that cannot be broken down into other substances by ordinary chemical means is called an element. All elements, and thus all substances, are ... - membrane bound sacs, usually containing pigments.  Chloroplasts are a type of plastid that contains a green pigment complex called chlorophyl.  It is the pigment complex that transforms the energy of sunli...

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