Explain the difference between sequential and direct file access. A. Sequential access to data is used when the data has to be read from the start, in sequence. It is the norâ¦mal method of access for magnetic tape. Direct access is used when it is possible to jump directly to a file or data item without reading through all the items stored before it.
melanin (meËÂ·lÂ·nin), n a substance produced by melanocytes found in the deepest layer of the epidermis; protects the skin from the effects of the sun's harmful rays. Variations in skin color are a result of the level of melanin produced by each individual.
Human skin contains specialized cells, called melanocytes, which are located at the base of the epidermis. These cells are programmed to manufacture a brown pigment, called melanin, in response to exposure of skin to sunlight.