Limestone is a sedimentary rock that is composed primarily of calcite. It forms from both the chemical precipitation of calcium carbonate and the transformation of shell, coral, fecal and algal debris into calcite during diagenesis.
To calcu-late the PPF, suppose that Crusoe puts all 8 hours into gathering fruit, so that he gets 36 pounds. But there is no time left for fishing, so he gets 0 pounds of fish. If he takes an hour off from gathering fruit, he gets 35 pounds of fruit and has an hour in which to fishâso he gets 4 pounds of fish.The rest of the PPF is con-structed similarly. 2.ut there is no time left for fishing, so he gets 0 pounds of fish. If he takes an hour off from gathering fruit, he gets 35 pounds of fruit and has an hour in which to fishâso he gets 4 pounds of fish. The rest of the PPF is con-structed similarly. 2.
Green plants and algae occupy the producer level because they can use the energy of the sun, plus carbon dioxide and water, to produce glucose and oxygen. The next trophic level is primary consumer or herbivore. These are organisms that gain food energy by eating the producers. An example is a caterpillar consuming leaves or a rabbit feeding on crops. The next trophic level is the secondary consumer.