Special types of chromosomes

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

The preceding section in this section dealing with chromosomes in eukaryotes was devoted to structure and function of chromosomes as observed in mitotic or meiotic cells in plants and animals. In certain organisms there are special tissues where these chromosomes take up a special structure. Lampbrush chromosomes of the vertebrate oocyte and giant chromosomes of salivary gland cells of dipterans are such special types of chromosomes. Due to special significance of these chromosomes, a relatively detailed account of these two types of chromosomes will be presented.