It will eventually push through the wall of a lymph vessel or blood vessel and clumps of cancer cells will break off and travel around the body. The cancer can then be very hard to cure. The whole body is soon seeded with tumours of the original cancer cell type. Usually, it is then only a matter of time before vital functions are interfered with and the patient dies. Cloudiness in the lens of the eye, or the covering capsule of the lens, dimming the eyesight, producing distorted images, and eventually causing blindness.
Cataracts can have several causes, one of which is prolonged exposure to too much sunlight.
DNA is present in the nucleus and other organelles such as mitochondria and chloroplasts. Energy which travels through space in the form of waves. All electromagnetic radiation travels at light speed - 300,000 kilometres per second in a vacuum. The basic unit of inheritance. A gene is a segment of DNA that specifies the structure of a protein or an RNA molecule.