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 [...]
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 [...]