The Six Kingdoms. When Linnaeus developed his system of classification, there were only two kingdoms, Plants and Animals. But the use of the microscope led to the discovery of new organisms and the identification of differences in cells.A two-kingdom system was no longer useful.Today the system of classification includes six kingdoms.he Six Kingdoms. When Linnaeus developed his system of classification, there were only two kingdoms, Plants and Animals. But the use of the microscope led to the discovery of new organisms and the identification of differences in cells.
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Photo Therapeutic Keratectomy-PTK Laser eye surgery. PTK is a surgical procedure which is mainly used to treat scars on the cornea and any other type of corneal surface disease.These include corneal dystrophy and epithelial erosion syndrome.he aim of this procedure is to treat surface level corneal disease and NOT to remove the need to wear glasses or contact lenses. However, this treatment can be combined with PRK which means that it has both a medical and cosmetic application.