In this article we will discuss about causes for the oncogenicity of the oncogene. When the oncogene from human bladder carcinoma cells was sequenced, and its sequence was compared with the sequence of the homologous proto-oncogene, its oncogenicity was found to result from a single base pair substitution. That is, a single base pair difference was shown to correlate with [...]
In this article we will discuss about the Mendel's tri-hybrid and multi-hybrid crosses. Mendel extended his observations to tri-hybrid crosses involving three pairs of contrasting characters. The characters he considered were: seed shape—smooth (S) vs. wrinkled (s); colour of cotyledons—yellow (Y) vs. green (y); and flower colour—violet (V) vs. white (v). The F1 hybrid produces 8 types of gametes. These [...]
In this article we will discuss about the role of environment in changing the form and degree of expression of some genes resulting in a corresponding change in the phenotype. Penetrance and Expressivity: The presence of a gene does not always bear an absolute relationship with the appearance or absence of a trait. In the ABO blood group system, the [...]