Physical Basis of Heredity 1. The Nucleus and the Chromosome

Content
Physical Basis of Heredity 1.  The Nucleus and the Chromosome
The Nucleus 
Significance of nucleus : Hammerling's experiment
Number, shape and size of nucleus
Nucleus in prokaryotes and eukaryotes
Nuclear envelope
Nuclear pore complex and nucleocytoplasmic traffic
Nucleolus
Chromosomes
Number, size and shape of chromosomes
Morphology of chromosomes
Karyotypes
Euchromatin and heterochromatin
Constitutive and facultative heterochromatin
Single-stranded and multi-stranded hypotheses for chromosomes
Chemical composition of chromosomes
Infrastructure of chromosomes
Function of chromosomes
Special types of chromosomes 
Lampbrush chromosomes
Salivary gland chromosomes
B-Chromosomes
Prokaryotic Nucleoids

In earlier five topics, preliminary and basic information on principles of genetics was presented in its historical perspective. Further ideas and principles of genetics will be presented in further sections in the background built in these five topics. However, before this additional information is presented, one should understand about the physical entities present in the cell, which axg responsible for the transmission and expression of hereditary characters. This aspect of genetics will be discussed in this and the next three sections. However, the discussion on these entities at the molecular level involving chemistry of the molecules responsible for heredity.