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 five main DNA repair mechanisms that are studied in eukaryotes. The mechanisms are: 1. Photo-Reactivation or Photo-Repair 2. Dark or Excision Repair 3. Nucleotide Excision Repair 4. Mismatch Repair 5. Post-Replication Repair. Mechanism # 1. Photo-Reactivation or Photo-Repair: This mechanism was discovered when bacteria that had been heavily irradiated with UV rays [...]