Cell Division Test
Review
CHROMOSOME
•DNA that coils
around a protein
• CHROMATIN
• Long thin UNCOILED
strands of DNA.
• Form between divisions
CHROMATID
• At the beginning of cell
division
• Coiled DNA
HISTONE
•The protein a
chromatid wraps
around to make a
chromosome.
Haploid cells/
Sex cells/Gametes
• For all organisms in general
• It only contains 1 chromosome
from each homologous pair
and 1 sex chromosome
• A cell that contains ½ the
amount of normal
chromosomes
EXAMPLES
• Diploid # of an organism
is 36
• Haploid # would be?
• 18
Diploid cells/Body cells/
Somatic cells
• For all organisms in general
• A cell that contains all of its
homologous pairs of
chromosomes and its pair of
sex chromosomes
• Ex 78
Homologous
Chromosomes
• Chromosomes that are similar in
size and shape and
make a pair.
• They are not exact copies
•Sister chromatids
• Exact copy of a chromosome
MITOSIS
Dividing of diploid
cells to make more
diploid cells
MEIOSIS
The making of sex
cells/ haploid cells
or gametes from
diploid cells
THREE STAGES
G1 or Gap 1
1. Cell Membrane and
cytoplasm double
•Cell doubles in size
2. S stage or Synthesis
Stage-
Chromosomes/DNA
Replicate or Double
3. G2 or GAP 2–
•Cell doubles all other
organelles
Cytokinesis
• The final stage of the cell cycle where the
cytoplasm and the cell membrane split
creating 2 cells
• Plant cell form a cell plate between the 2
nuclei which forms a cell wall
HUMAN CELLS
• Diploid Cells
• 46
• Haploid
• 23
Remember
•
•
•
•
Diploid Cells---have NO Genetic Variation---Identical Cells
They are made to repair, replace and growth
Asexual reproduction---offsprings are
EXACTLY the same as parent.
Remember
• Haploid Cells---• have Genetic Variation---COMBO of
parents genes
• They are made for sexual reproduction--offsprings are NO EXACTLY the same as
parent.
• Any cell that is a result of a division
• Number of
chromosomes in each
cell in each phase
•Know how this
works for other
organisms
•Study Picture
handout of Mitosis
• Prophase
•Metaphasee
• Anaphase
Telophase
Meiosis
• Homologous Chromosomes Separate
during Anaphase I
• Sister Chromatids Separate during
Anaphase II
• End Result ---4 Haploid Cells
4 Sex Cells
4 Gametes
Numbers of Meiosis
•
•
•
•
•
•
Interphase—46/1cell
Prophase II—46/2cells
End Interphase---92/1 cell Metaphase II-46/2cells
Prophase I---92/1 cell
Anaphase II—46/2cells
Metaphase I—92/1 cell
Telophase II—23/4 cells
Anaphase I—92/1 cell
Telophase I—46/2 cells
• Know how this works for other organisms
• Organisms go through Meiosis for Sexual
Reproduction----variation in species
• Cells as a result---Sex cells, haploid cells,
Gametes
Open Constructive Response
• Answer Following Slides
PROPHASE
• Nuclear membrane and
nucleolus disappear
• Spindle fibers and centrioles
appear
• Chromosomes become visible
METAPHASE
META=MIDDLE
Spindle fibers pull
chromosomes to the center of
the cell.
ANAPHASE
SISTER
CHROMATIDS
SEPARATE
TELOPHASE
Nuclear Membrane and
nucleolus reappear
Centrioles and spindle fibers
disappear
Cell membrane splits into two
new cells