Download Learning Target

Learning Target
6. Recognize the type of daughter cells formed through mitosis and
their chromosome number as compared to the parent cell.
1-1
Chromosome Number
• Each species has unique chromosome # no relationship to
complexity
• Diploid--2n  2 copies of each chromosome (1/Mom & 1/Dad)
(Homologous pairs)
• All somatic cells (body cells) are 2n
• Haploid--1n  1 copy of each chromosome (either Mom’s or
Dad’s)
• Only gametes (sperm/eggs) are 1n
1-2
Mitosis (Animal Cells)
• After “S” phase replicates DNA
• Division of nucleus ONLY !
chromosome # stays constant
• Centromere divides  each
chromatid becomes a daughter
chromosome
• M checkpoint-stops if
chromosomes not aligned
• Prophase
• Metaphase
• Anaphase
• Telophase
1-3
Prophase
•
5 “events”  memorize them!
1. Chromatin coils  chromosomes appear
2. Nucleolus disappears
3. Nuclear membrane
disappears
4. Centrioles & asters appear  move to
opposite poles of cell
5. Spindle fibers appear
1. Polar fibers  centriole to centriole
2. Kinetochore fibers 
centriole to
centromere
1-4
1-5
Metaphase
• Kinetochore fibers
push chromosomes to
middle of cell
1-6
1-7
Anaphase
• Kinetochore fibers separate 
break centromeres  pull
chromatids to opposite poles of
cell
• Characteristic “V” shape
1-8
1-9
Telophase
• Reverse of Prophase
1-10
1-11
Mitosis—Plant Cells
• Mitosis in plant cells
• Same phases as animal cells
• Plants don’t have centrioles or asters
1-12
1-13
Cytokinesis
• Cytoplasm divides after mitosis
• Animals  Cleavage “furrow” (edges
in)
• Plants  Cell Plate (center out)
• Mitosis animation:
• http://www.sumanasinc.com/webcontent/anisamples/majorsbi
ology/mitosis.html
• http://vcell.ndsu.edu/animations/mitosis/movie-flash.htm
1-14
Image found 11/29/4 on https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcT5zNgamn0R-M0Lufaxzvr5aXdjNYL1fb7lelcyz6w4Wwc7PEsTFQ
1-15
Mitosis in Prokaryotes
• Asexual reproduction (Binary
Fission)  Cloning
• 2 identical daughter cells
• Single DNA strand duplicates
 cell elongates, pinches in
half
1-16
Benefits of Mitosis
• Genetically identical
daughter cells
• Take advantage of
good conditions
rapidly
• Algal blooms
1-17