Some investigators of 1950s focused their attention on viruses containing protein and RNA, but no DNA. The poliomyelitis virus, influenza virus and the virus that causes mosaic disease in tobacco plants (TMV) were thus shown to have genes made of RNA. Earlier in 1935 W. M. Stanley had reported the isolation of a crystalline protein from infected tobacco plants, which [...]
In this article we will discuss about the meaning of transformation. Transformation is the process of adding a foreign DNA fragment from a donor genome into genome of a recipient cell. The donor fragment passes through the cell membrane of the recipient cell (which may or may not belong to the same species) and becomes incorporated into the latter's genome [...]
In this article we will discuss about the biochemical evidence that genes are made of DNA. Quantitative estimations of DNA carried out on various organisms revealed the following constant features, providing additional support for DNA as the genetic material: 1. The amount of DNA per cell in an organism or a given species is remarkably constant and cannot be altered [...]