There are three types of genetic disorders: 1  Single-gene disorders, where a mutation affects one gene. Sickle cell anemia is an example. 2  Chromosomal disorders, where chromosomes (or parts of chromosomes) are missing or changed. Chromosomes are the structures that hold our genes. 3  Complex disorders, where there are mutations in two or more genes.
OSI model. The Open Systems Interconnection model (OSI model) is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to their underlying internal structure and technology. Its goal is the interoperability of diverse communication systems with standard protocols.
The current standard was published in 1996. The official title for the model is the ISO OSI (Open Systems Interconnection) Reference Model since it describes or relates to connecting systems that are open for communication with other systems. In the model, the functions of the communication system are standardized by categorizing them into abstract layers.