Carbon dioxide exists naturally in the atmosphere as a result of the earth's carbon cycle. It is also there as a result of man's activities in burning fossil fuels (coal, oil â¦ and natural gas), which releases long-stored carbon dioxide to add to the greenhouse gases already there.
Credit for developing cell theory is usually given to three scientists: Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow. In 1839. I found this answer on examvillâ¦e.com, helped me complete my homework assignment.
Cell Theory. The discovery of the cell was made possible by the invention of the microscope, which was made possible by improved lens-grinding techniques. Antoni van Leeuwenhoek (1632-1723), a Dutch tradesman, learned to grind lenses and assemble them into simple microscopes.