In this article we will discuss about the definition of conjugation in bacteria. The occurrence of recombination by sexual union was first shown experimentally in 1946 by Joshua Lederberg and E.L. Tatum in E. coli. They took two auxotrophic strains neither of which could grow on minimal medium due to mutation in genes controlling synthesis of vitamins thiamine and biotin, [...]
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 [...]