The nucleus and nucleolus are organelles found within eukaryotic cells. The nucleus contains most of the cell's genetic material and is surrounded by a double nuclear membrane. It functions as the control center of the cell. The nucleolus is located within the nucleus and is the site of ribosomal RNA transcription. It has three main components - fibrillar center, dense fibrillar component, and granular component. The nucleolus is made up of proteins and RNA and its main function is to produce ribosomal RNA.

1. Nucleus and Nucleolar
Presented by : Patel Rinku
MSc sem :1
CBO : 403
Department of life sciences,
H. N.G.U. , Patan.

2. Contents
 Nucleus :
• Introduction
• Ultra structure chemical nature
 Nucleolar :
• Introduction
• Ultra structure chemical nature
 Nucleolar chromosome

3. Nucleus
Introduction :
• The nucleus was the first organelle to be
discovered. The nucleus also known as the
control centre is a membrane enclosed
organelle found in eukaryotic cells.
• It contains most of the cell's genetic material.
• The main structures making up the nucleus is
the nuclear envelope a double membrane that
encloses the entire organella.

5. Ultra structure
• Nucleus is the controlling centre where the
master molecule DNA directs the entire activity
of the cell.
Nuclear membrane :
• The nuclear membrane covers the nucleus.
• It allows material to flow in and out of small
pores.

7. Chemical nature
• The nucleus contains mainly nucleoproteins
composed of nucleic acid and proteins, besides
enzymes and inorganic salts.
• The following is the percentage of different
components of nucleus of mammalin liver cells in
interphase, determined by spectrophotometric
analysis :
DNA 9% Residual protein 14%
RNA1% other acidic proteins 65%
Histone protein 11%

9. Nucleolar
• The nucleolus is a non - membrane bound
structure Composed of proteins and nucleic
acids found within the nucleus.
• The ribosomal RNA is transcribed in the
nucleolus.

11. Ultra structure
• Three major Components of the nucleolus
are recognized :the fibrillar center (FC), the
dense fibrillar Component (DFC), and the
granular Component (GC).
• Transcription of the rDNA Occurs in the FC.
• The GC Contains the protein
nucleophosmin.

13. Chemical nature
• The main Compositions of the nucleolus are
protein, RNA and a trace of DNA.
• This structure is made up of proteins and
ribonucleic acids (RNA).
• Its main function is to rewrite ribosomal
RNA (rRNA) and combine it with proteins.
• Nucleolus is usually divided into three parts
namely fibrous, granular and matrix.

14. Nucleolar chromosome
• Chromosomes are long string - like a structures.
• They are coiled to fit into the nucleus.
• Chromosomes are made of DNA.
• They are the genetic information of the
organism.
• Also called chromatin when it is uncoiled.

16. References
 Cell biology, Genetics, Molecular Biology,
Evolution and Ecology
P. S. Verma and agarwal
https://www.ncbi.nlm.nih.gov

17. Thank you