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Nucleus
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The Brain of the Cell
By: Bryonna Aldubayan
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Definition
Function
Significance
Structure and Components
Nuclear Envelope and Pores
Nucleolus
Nucleoplasm
Mitosis/Meiosis
Malfunctions/Disease
Outline
Definition
In an atom:
The nucleus is the center of an atom
which contains the protons and neutrons
In a cell:
The nucleus is the structure that contains
the cell's genetic material (DNA) and
controls the cell's activity in a eukaryotic
cell.
Function
• The nucleus regulates all cell activity,
growth and reproduction. It controls the
cell through protein synthesis.
• Protein Synthesis is the process by which amino acids
are arranged linearly into proteins through the
involvement of ribosomal RNA, transfer RNA,
messenger RNA, and various enzymes
Significance
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The nucleus contains DNA which
contains coded instructions needed for
cell reproduction and also produces
proteins that control metabolism and
other cell functions.
Structure
• The nucleus is a spherical
double membrane organelle.
The nucleus contains:
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Nuclear Envelope
Pores
Nucleolus
Nucleoplasm
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Components
Nuclear Envelope
&
Pores
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The nuclear envelope is a double phospholipid bilayer
membrane which surrounds the genetic material in
eukaryotic cells.
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Outer membrane
Inner membrane
The nuclear membrane is dotted with thousands of
small holes called nuclear pores that allow material to
diffuse in and out of the nucleus.
Nucleolus
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Small, dense region
Generally located in the center of the nucleus.
It is made of proteins and ribonucleic acids.
It is the location where the assembly of
ribosomes begin.
Nucleoplasm
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Highly Viscous Liquid
Enveloped by the inner membrane of the
nuclear envelope.
Surrounds the chromatins and nucleolus
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Mitosis
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Involves the
replication of all
eukaryotic cells
except that of sex
cells.
Replication
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Meiosis
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Replication of only
sex cells.
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Mitosis
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Cancer
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Uncontrolled
abnormal cell
division
Spread through
blood stream and
lymph system
100 different types
Malfunctions
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Meiosis
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Down Syndrome
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Trisomy 21
(nondisjunction)
Translocation
Mosaicism
3 different types
Cancer
Cancer
Down Syndrome
Typical Cell Division
Down Syndrome
• Results in an embryo
• 3 copies of chromosome 21
• Sperm or egg fails to separate
Trisomy 21 (nondisjunction)
Down Syndrome
• Chromosome 21 takes
place in 1 initial cell
division
• Mixture of 2 cell types
Mosaic
Down Syndrome
Works Cited
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"What Is Cancer?." - National Cancer Institute. N.p., 7 Mar.
2014. Web. 15 Mar. 2014.
<http://www.cancer.gov/cancertopics/cancerlibrary/whatis-cancer>.
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"What Is Down Syndrome?." The National Advocate for
People with Down Syndrome Since 1979. N.p., n.d. Web. 15
Mar. 2014. <https://www.ndss.org/DownSyndrhttps://www.ndss.org/Down-Syndrome/What-IsDown-Syndrome/ome/What-Is-Down-Syndrome/>.
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"nucleus Images - Google Search." nucleus Images - Google
Search. N.p., n.d. Web. 15 Mar. 2014.
<https://www.google.com/search?q=nucleus&source=lnms
&tbm=isch&sa=X&ei=r7kmU_rSOKvr0QGf3oCYBA&sqi=2
&ved=0CAcQ_AUoAQ&biw=1366&bih=650>.