Transcript Prokaryotic cell reproduction Binary Fission

Prokaryotic cell reproduction
Binary Fission
Eukaryotic Cell Cycle
Eukaryotic Cell Reproduction: Mitosis & Meiosis
Mitosis: cell reproduction for growth and replacement of
cells. This makes identical copies (clones)
Meiosis: cell reproduction for the production of gametes,
such as egg and sperm (sex cells)
How many chromosomes in a human cell such as a skin cell?
How many chromosomes in egg and sperm?
Human Karyotype
Is this person male or female?
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chromosomes
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chromosomes
replication
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chromatids
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chromatids
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chromosomes chromosomes
Mitosis
One division
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Meiosis
Two divisions
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chromosomes
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Mitosis: cell reproduction for growth and replacement of
cells. This makes identical copies (clones)
What are some examples of mitosis in the body?
• Cuts and scrapes
• Embryonic growth
• Aging
• Stomach cells
What are some examples of mitosis in other organisms?
• Asexual reproduction (budding and fragmentation)
• Plants: growth of roots and stems
• Regeneration (starfish arm, lizard tail)
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chromosomes
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chromosomes
replication
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chromatids
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chromatids
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chromosomes chromosomes
Mitosis
One division
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Meiosis
Two divisions
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chromosomes
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Sister Chromatids
centromere
DNA Replication
Chromosome
Sister Chromatids
Phases in Mitosis
• Interphase: DNA replication
• Prophase: chromosomes thicken, nucleus
disappears
• Metaphase: chromosomes line up at
center
• Anaphase: centromeres split, sister
chromatids separate
• Telophase: cytokinesis, division of the
cytoplasm
Applications of Mitosis?
Cancer = abnormal
growth of cells
Control of the Cell Cycle
MPF
is a protein
that triggers
mitosis.
Where is MPF
in high amounts
and in low
amounts?
Regulation of Cell Cycle
• What controls cell reproduction?
• MPF = Maturation Promoting Factor
MPF = cyclin + cdk (cdc2)
Protein Kinase = activates other proteins
i.e. spindle fibers that move chromosomes
• Two functions of MPF:
1. triggers mitosis
2. activates enzymes to breakdown cyclin
(negative feedback)
Cancer
• Transformation = process that converts a normal
cell to a cancer cell
• Tumor = loss of cell cycle control = abnormal
growth of cells
• Benign = noncancerous,
Malignant = cancerous
• Metastasis = spread rate of a malignant cancer
to locations other than their origin
(tumor cells enter blood vessels and travel to other
parts of the body)
Meiosis: cell reproduction for the production of gametes,
such as egg and sperm (sex cells)
•Meiosis cuts the number of chromosomes in half
•Meiosis occurs in gonads
•Gonads are reproductive organs
(such as ovaries and testes)
•2 divisions
1st Meiotic division
Interphase
Prophase I
Metaphase I
Anaphase I
Telophase I
2nd Meiotic division
Prophase II
Metaphase II
Anaphase II
Telophase II
Homologous Pair (Homologous
Chromosomes)
• Chromosomes that carry genes in the
same place for the same traits
• One is maternal in origin (from the egg)
• The other is paternal in origin (from the
sperm)
Hair color
Eye color
Skin tone
hitchikers
earlobes
widow’s
1st Meiotic Division
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Interphase: DNA replication
Prophase I: crossing over
Metaphase I: independent assortment
Anaphase I: homologous pairs separate,
centromeres intact
• Telophase I: cytokinesis
2nd Meiotic Division
• Prophase II: reorganization, no crossing
over
• Metaphase II: chromosomes line up with
centromere on line
• Anaphase II: centromere splits, sister
chromatids separate
• Telophase II: cytokinesis