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 [...]
In this article we will discuss about:- 1. Gross Structure of Chromosomes 2. Specific Gene Sequences in Chromosomes 3. Chromosome Banding 4. Synaptonemal Complex 5. Strandedness 6. Types of Specialised. Gross Structure of Chromosomes: The chromosome consists of two rod-like structures called chromatids joined with each other at the primary constriction or centromere. The portions of the chromatid on either [...]