In this article we will discuss about the repeated sequence of chromosomal DNA. Eukaryotic genomes contain large amount of repetitive sequences, sometimes present in hundreds or thousands of copies per genome. The understanding of repetitive sequences is based on studies conducted on denaturation (separation of DNA double helix into its two component strands) and renaturation (re-association of the single strands [...]
In his article we will discuss about the role of nucleolus in production of ribosomes (explained with diagram). The nucleolus is the site for rRNA transcription and processing as well as for assembly of ribosomal subunits. The nucleolus is organised at the nucleolus organising regions (NORs) of some chromosomes. These chromosomal regions contain the genes for 5.8S, 18S and 28S [...]
In this article we will discuss about the structure of nucleosome. When chromatin or whole chromosomes are spread on an air-water interface and examined in the electron microscope, fibers 250 Å in diameter are observed. These are de-oxy-nucleoprotein fibres in which DNA is complexed with protein. Removal of proteins by various methods reveals the 10 nm fibre (1nm = 10 [...]