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 [...]
The below mentioned article provide notes on reverse mutation. When a mutation changes the wild type normal genotype to a mutant type, as is more often the case, the event is called a forward mutation. This is in contrast to reverse mutations in which the mutant genotype changes to the original wild type. In micro-organisms auxotrophs reverting to prototrophs are [...]