The nucleus

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
Number, size and shape of chromosomes
Morphology of chromosomes
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
Prokaryotic Nucleoids

Robert Brown for the first time in 1833 discovered a prominent body within the cell and termed it nucleus. A synonymous term for this organelle is the Greek word karyon. The nucleus can be called as the controlling centre of the cell, since it contains the chromosomes and the genes, which control all activities of an individual cell. The chromosomes which are present within the nucleus are responsible for deciding whether a fertilized egg will develop into a cow, a mango tree or into a man.