Download 2.5 Cell Division

2.5 Cell Division
Oh Yeah!
By Sam Terrell
2.5.1 Outline the stages in the cell cycle, including interphase (G1,S,G2),
mitosis and cytokinesis. (ch. 12 pg. 217)
 Interphase accounts for 90% of the cycle.
 Divided into subphases: G1 Phase (1st Gap), S Phase (Synthesis of DNA), and
G2 Phase (2nd Gap).
 In the G1 phase, a cell grows until it reaches the S phase where chromosomes
are duplicated, then it continues to grow in the G2 phase.
 The S phase is the only phase of the cell cycle when chromosomes are
duplicated.
 After G2 Phase, the cell undergoes Mitosis (Prophase, Metaphase, Anaphase,
Telophase); this is where the nucleus divides and distributes its chromosomes to
the daughter nuclei.
 Then, in cytokinesis, the cytoplasm of the cell divides producing two daugher cells
An image of the cell cycle for visual learners…
 Isn’t it pretty?
QuickTime™ and a
decompressor
are needed to see this picture.
 If you didn’t already know, the answer is yes.
2.2.5 State that tumors (cancers) are the result of uncontrolled cell
division and that these can occur in any organ or tissue.
 Obviously, all you need is that statement for the quizzes, but just
think of this and you’ll never forget what a tumor is:
QuickTime™ and a
decompressor
are needed to see this picture.
Another free-be:
2.5.3 State that interphase is an active
period in the life of a cell when many
metabolic reactions occur, including
protein synthesis, DNA replication and
an increase in the number of
mitochondria and/or chloroplasts
2.5.4 Describe the events that occur in the four phases of mitosis
(prophase, metaphase, anaphase, and telophase). See ch.12 pg. 218
for an awesome diagram of mitosis.
 Prophase: the chromatin supercoils and condenses into
chromosomes; the nucleoli disappears; each duplicated
chromosome appears as a pair of sister chromatids joined
together by a centromere; the centrosomes move to opposite
poles of the cell, starting the formation of microtubules.
 Metaphase:The centrosomes are now on opposite poles of the
cell; the chromosomes align on the equator; microtubules have
attatched to the centromere of each sister chromosome.
 Con’t on next…
2.5.4 (con’t)
 Anaphse: the paired centromeres of each chromosome separate,
leaving sister chromatids; now all are separate chromosomes;
chromosomes pulled to opposite sides of the cell.
 Telophase: the nuclear envelope begins to develop; chromatin
begins to uncoil; the formation of a cleavage furrow begins.
2.5.5 Explain how mitosis produces two genetically identical nuclei.
 DNA is coiled in the nuclear envelope forming chromosomes.
 The chromosomes are separated, moving to opposite poles of
the cell.
 The cell divides into two sister cells forming 2 genetically identical
nuclei.
 Note: this is the abridged version of what we just talked about.
2.5.6 State that growth, embryonic development, tissue repair, and
asexual reproduction involve mitosis.
State that, and your done with 2.5 Cell
division, not so bad right?
Enjoy!
Vocab:
Interpahse, G1, S Phase, G2, Mitosis,
Prophase, Metaphase, Anaphase,
Telophase, Cytokinesis, Cytoplasm,
Supercoiling, Chromosomes,
Chromatids, Centromere,Nuclear
Envelope, and Cancer.