explain bacis about cell nucleus

1. NUCLEUS
Presented by:
Warda Irfan

2. Content
NUCLEUS AND ITS COMPONENTS
 Nuclear envelop
 Nucleoplasm
 Nucleolus
 chromosome

3. NUCLEUS
The nucleus is a membrane-bound organelle
that contains genetic material (DNA) of
eukaryotic organisms. As such, it serves to
maintain the integrity of the cell by facilitating
transcription and replication processes.

5. Where is nucleus found in cell?
 In animal cell, It is located in the center of
cell.
 In plant cell, It is located at peripheral
region due to presence of large vacuole

6. Animal cell Plant cell

7. FUNCTIONS OF NUCLEUS
• It controls the heredity characteristics of an organism.
• It main cellular metabolism through controlling synthesis of
particular enzymes.
• The nucleus controls and regulates the activities of the cell
• It is responsible for protein synthesis, cell division, growth
and differentiation.
• Stores heredity material in the form of deoxy-ribonucleic acid
(DNA) strands. Also stores proteins and ribonucleic acid
(RNA) in the nucleolus.
• It also regulates the integrity of genes and gene expression.

8. NUMBER OF NUCLEUS
 Mononucleate cell
Cell having one nucleus
 Binucleate cell
Cell having two nucleus
 Multinucleate cell
Cell having many nucleus
Mononucleate
cell
Binucleate
cell

9. When nucleus is visible?
 Nucleus is visible when cell is not dividing
stage.
 Under microscope

10. COMPONENTS OF NUCLEUS
 Nuclear envelop
 Nucleoplasm
 Nucleolus
 chromosome

11. NUCLEOPLASM
 Nucleoplasm is the fluid present between
nuclear membrane and nuclear materials.
 It is similar to cytoplasm

12. NUCLEAR MEMBRANE
 An envelop that surround nucleus is
nuclear membrane.
 It separates cytoplasm and nuclear
material.
 Nuclear membrane is continuous with
endoplasmic reticulum
 It has two membranes (inner and outer).
 Nuclear membrane have pore called as
nuclear pores

14. ROLE OF NUCLEAR PORES
 Number of nuclear pores vary from cell to
cell
 An egg has 30,000 pores in nuclear
membrane
 Nuclear pores allow material to pass
through it from cytoplasm to nucleus and
vise versa.

15. NUCLEOLUS
Nucleolus is darkly stained
structure within nucleus.
 It has no membrane.
 Nucleolus synthesize rRNA
 Ribosomes assembled in
nucleolus.

16. CHROMOSOMES
Chromosomes are thread-like structures
located inside the nucleus of animal and
plant cells. Each chromosome is made of
protein and a single molecule of
deoxyribonucleic acid (DNA).

17. STRUCTURE OF
CHROMOSOME
 Under compound microscope,
chromosome appear to be
made off chromatids (arms )
and centromere.
 Centromere is the point where
chromatids are attached.

18. Chromosomes are visible in cell division

19. ROLE OF CENTROMERE
 Centromere is the
point where
chromatids
 During cell division
spindle fibers attached
to centromere.
Spindle
fibers

20. COMPOSITION OF CHROMOSOME
 Chromosome is composed of DNA and
proteins.
 Genes are located on chromosomes
 Genes contain hereditary information that
pass from one generation to next generation.

21. Composition of chromosomes
protein
s
DNA

22. NUMBER OF CHROMOSOME (cont….)
The number of chromosomes in a specie
remain same from generation to other
generation.

23. NUMBER OF CHROMOSOME (cont….)
Number of chromosomes in
Man 46
Frog cells 26
Fruit fly (Drosophila milanogester) 8
Onion 16
Potato 48

24. NUMBER OF CHROMOSOME (continue)
In human
 Number of
chromosomes in
somatic cell is 46 and
in germ cells it is half
(23)

25. MODEL

27. ACTIVITY

28. Cheek Cells Under a Microscope
 Cheek cells observe
under microscope
 Observe nucleus and
other cell organelle
nucleus