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 [...]
In this article we will discuss about the heterochromatin and euchromatin in eukaryotic chromosomes. The terms "heterochromatin" and "euchromatin" were given by Heitz in 1928-29, although they had been discovered much earlier. Heterochromatic blocks observed during interphase were earlier termed as pro-chromosomes. The substance of which eukaryotic chromosomes are composed is known as chromatin; it contains DNA, protein and a [...]
The following points highlight the two main ways of representing chromosome set of species. The ways are: 1. Karyogram 2. Idiogram or Idiotype. Representing Chromosome: Way # 1. Karyogram: Photomicrographs of the chromosomes of a single representative somatic metaphase cell are clipped out and arranged in homologous pairs according to their size. If the chromosomes are small and there is [...]