In this way, the distinction between a definition of morality and a moral theory parallels the distinction John Rawls (1971: 9) drew between the general concept of justice and various detailed conceptions of it.
Leaves are the site of the food making process called photosynthesis. In this process, carbon dioxide and water in the presence of chlorophyll (the green pigment) and light energy are changed into glucose (a sugar). This energy rich sugar is the source of food used by most plants.
The organisms at the beginning of the food chain are called producers or autotrophs, such as plants and algae. Some make their own food using the sun's energy through photosynthesis and some producers use chemosynthesis to make their own food. Above them would be 1st level consumers, then 2nd level consumers and so on.