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 OSI Model: applications, devices, and protocols related to the OSI model Layers The Open Systems Interconnect Model, abbreviated as OSI Model, is one of the oldest networking models over which many modern protocols are based. There are basically sever different layers which are involved in the OSI Model; Physical, Data Link, Network, Transport, Session, Presentation and Application Layer.