The following point highlight the five main types of structural variation in chromosomes. The types are: 1. Deletion or Deficiency 2. Duplications 3. Translocations 4. Inversions 5. B-Chromosomes. Type # 1. Deletion or Deficiency: A deficiency means deletion of a small portion of a chromosome resulting in loss of one or more genes. A deficiency originates from breakage occurring at [...]
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 study of a complete chromosomes. For karyotype analysis, a sample of peripheral blood is drawn from an individual, the leukocytes separated and cultured for about 3 days. To stimulate growth and cell division phyto-haemaglutinin (PHA) is added. The dividing lymphocytes are arrested at metaphase stage by exposing them to colchicine. The cells [...]