Discovered by an English biologist Robert Brown in 1831. It is also know as the, “Brain of the cell” or “Control centre of the cell” On the basis of absence and presence of nucleus cell may be divided into Prokaryotes and Eukaryotes respectively. NUMBER- Mostly uninucleate Binucleate – Hepatocytes,Chondryocytes, fungi Polynucleate- Tapetal cell, myocytes Anucleated Cell- Red Blood cell Sieve tube element Component of Nucleus Nuclear membrane Nuclear pore Nucleoplasm Nucleolus Chromatin Nuclear Membrane :Also called the nuclear envelope, is a double membrane layer that separates the contents of the nucleus from the rest of the cell. The nuclear membrane is a lipid bilayer, meaning that it consists of two layers of lipid molecules. Outer Layer:  The outer layer of lipids has ribosomes, structures that make proteins, on its surface. It is connected to the endoplasmic reticulum. Inner Membrane: Network of fibers and proteins attached to the inner membrane is called the nuclear lamina. It structurally supports the nucleus, plays a role in repairing DNA, and regulates events in the cell cycle such as cell division and the replication of DNA.

1. Presented By
Debibandita Rout
Central university South Bihar

2. NUCLEUS…?
CELL
NUCLEUS..?
ATOMIC
NUCLEUS..
?
PHYSICIST BIOLOGIST

3. THE CELL NUCLEUS
• Discovered by an English biologist Robert
Brown in 1831.
• It is also know as the, “Brain of the cell” or
“Control centre of the cell”

4. • On the basis of absence and presence of
nucleus cell may be divided into Prokaryotes
and Eukaryotes respectively.
• NUMBER- Mostly uninucleate
Binucleate – Hepatocytes,Chondryocytes, fungi
Polynucleate- Tapetal cell, myocytes
Anucleated Cell- Red Blood cell
Sieve tube element

5. Position- Centrally (Animal cell )
Peripheral (Plant cell)

6. Component of nucleus
• Nuclear membrane
• Nuclear pore
• Nucleoplasm
• Nucleolus
• Chromatin

7. Nuclear Membrane
Also called the nuclear envelope, is a double
membrane layer that separates the contents of
the nucleus from the rest of the cell.
The nuclear membrane is a lipid bilayer,
meaning that it consists of two layers of lipid
molecules.
Outer Layer: The outer layer of lipids has
ribosomes, structures that make proteins, on its
surface. It is connected to the endoplasmic
reticulum.
Inner Membrane: Network of fibers and
proteins attached to the inner membrane is
called the nuclear lamina. It structurally supports
the nucleus, plays a role in repairing DNA, and
regulates events in the cell cycle such as cell
division and the replication of DNA.

8. • Nuclear Pores: Outer layer and inner layer fuse together to form pores.
They are made up of large complexes of proteins and allow certain
molecules to pass through the nuclear membrane.

10. NUCLEOPLASM:
• Similar to the cytoplasm of a cell,
the nucleus contains nucleoplasm, also known
as karyoplasm, or karyolymph or nucleus sap.
The nucleoplasm is a type of protoplasm, and
is enveloped by the nuclear envelope. The
nucleoplasm includes
the chromosomes and nucleolus.

11. Nucleolus
• Ribosome factory
• Predominant structure of nucleus
• Membraneless structure
• It is associated with the genes for ribosomal
RNAs. This the site of Rrna transcription,
ribosome assembly.

13. CHROMATIN
• The nucleoplasm contain many thread like
coiled and much elongated structure-
chrimatin fibres.
• Observe only in interphase
• During cell division it become thick called
chromosome.
• Chromatin fibres are two types
Heterochromatin- More compact DNA
Euchromatin- less compact DNA form

14. Function of Nucleus:
• The nucleus provides a site for genetic transcription..
• The main function of the cell nucleus is to control
gene expression and mediate the replication of DNA
during the cell cycle.

15. References
• https://youtu.be/g4jj10r-exE
• The cell a molecular approch, Jeffery.M
Cooper
• https://www.slideshare.net
• https://en.wikipedia.org/wiki/Cell_nucleus
• https://mmegias.webs.uvigo.es/02-english/5-
celulas/4-nucleolo.php

16. THANK YOU