vue - Virus-Structure, Genetics,Culture and Diseases....

Virus: Structure, Genetics, Culture and Diseases: Viruses are infectious agents. They are much smaller than the bacteria. Their approximate size ranges from 20 to 300 nm. Viruses are incapable of independent growth in artificial media. They can grow only in animal or plant cells or in microorganisms. Hence they are referred to as obligate intracellular parasites. They reproduce in these cells by replication. Replication is a process in which many copies or replicas of the viral component are assembled and made to represent the progeny. They lack metabolic machinery of their own to generate energy or to synthesize proteins. They depend on the host cells to carry out these vital functions. The bacterial viruses are called bacteriophages. These viruses infect the bacteria and multiply inside the bacterial body and cause the lysis of bacteria (lytic cycle) or integrate themselves with the bacterial genome (lysogeny). www.edufine.net