In this article we will discuss about the replication of eukaryotic chromosome. Taylor in 1958 used radioactive thymidine (3H-thymidine) to label Viciafaba root tip chromosomes. He showed that the chromosomes replicated in a semiconservative manner, and proposed that each chromatid was made up of a single DNA molecule. Thus each sister chromatid is composed of one of the two progeny [...]
In this article we will discuss about the structure and synthesis of telomere. Structure of Telomere: Molecular genetic studies have shown that the telomere consists of several short sequences which are tandemly repeated (Table 8.8). The general formula for the composition of the repeating units in one strand of the telomeres of all the eukaryotes is as follows: 5' Cn [...]
In this article we will discuss about the changes in chromatin structure during transcription. Displacement of nucleosomes: During transcription, some changes in the chromatin structure occur in the region of transcription. RNA polymerase is comparatively larger in size than the nucleosomes. The molecular weight of RNA polymerase is about 5,00,000 Daltons, while that of nucleosome is about 2,60,000 Daltons. Lewin [...]