5. All
organisms have
different numbers of
chromosomes.
A body cell in an adult
fruit fly has 8
chromosomes: 4 from
the fruit fly's male
parent, and 4 from its
female parent.
6. These
two sets of chromosomes
are homologous.
Each of the 4 chromosomes that
came from the paternal has a
corresponding chromosome from
the maternal
7. A cell that contains both sets of
homologous chromosomes is said to
be diploid.
The number of chromosomes in a
diploid cell is sometimes represented
by the symbol (2n)
13. MEIOSIS I:
Prophase I
Each
chromosome
pairs with its
corresponding
homologous
chromosome to
form a tetrad.
There are 4
chromatids in a
tetrad.
14. When
homologous chromosomes form
tetrads in meiosis I, they exchange
portions of their chromatids in a process
called crossing over.
Crossing-over produces new
combinations of alleles.
17. Nuclear
MEIOSIS I:
Telophase I and
Cytokinesis
membranes form.
The cell separates into two
cells.
The two cells produced by
meiosis I have
chromosomes and alleles
that are different from each
other and from the diploid
cell that entered meiosis I.
18. MEIOSIS ll
The
two cells produced by meiosis I
now enter a second meiotic division.
Unlike meiosis I, neither cell goes
through chromosome replication.
Each of the cell’s chromosomes has 2
chromatids.
19. Meiosis II
Telophase I and
Cytokinesis I
Meiosis II
Prophase II
Metaphase II
Anaphase II Telophase II
and
Cytokinesis
20. MEIOSIS II:
Prophase II
Meiosis
I results
in two haploid (n)
daughter cells,
each with half the
number of
chromosomes as
the original cell.
22. MEIOSIS II
Anaphase II
The
sister
chromatids
separate and move
toward opposite
ends of the cell.
23. MEIOSIS II
Telophase II and Cytokinesis
Meiosis
II results in
four haploid (n)
daughter cells
http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120074/bio19.swf::Stages%20of%20Meiosis
25. In
many female animals, only one egg
results from meiosis.
The other three cells, called polar
bodies, are usually not involved in
reproduction.
26. MITOSIS
• Cells produced by mitosis have the
same number of chromosomes and
alleles as the original cell.
• Mitosis allows an organism to grow
and replace cells.
• Some organisms
reproduce asexually by mitosis.
27. MEIOSIS
Cells produced by meiosis have half the
number of chromosomes as the parent
cell.
These cells are genetically different from
the diploid cell and from each other.
Meiosis is how sexually-reproducing
organisms produce gametes.
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Feder, A. (2013). http://www.slideshare.net/jojatk/meiosisglencoe?qid=62b29050-df7e-4e20-a3589aec8af199ae&v=qf1&b=&from_search=12
Gquinnn617,(2014), Median Genetics and meiosis.
http://www.slideshare.net/gquinn617/09-genetics?qid=62b29050-df7e-4e20a358-9aec8af199ae&v=qf1&b=&from_search=6
Rozeka, P. (2013). Biology, cell division meiosis.
http://www.slideshare.net/rozeka01/biology-unit-4-cell-division-meiosisnotes?qid=62b29050-df7e-4e20-a3589aec8af199ae&v=qf1&b=&from_search=10
Swan,J. (2011). Meiosis and Sexual Life Cycle.
http://www.slideshare.net/jayswan/chapter-12-presentation-6504580