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http://wikieducator.org/images/0/02/Labelled_animal_cell_for_cell_worksheet.JPG
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MITOSIS
Texts: See Ross’s Histology, 4 ed. (pp. 60-62; 68-69) for additional reference.
Part 1: Cell Cycle
The cell cycle has two principal phases, each of which is comprised of a number of subdivisions:
a) Interphase
-G1 = gap 1 phase, a period of cell growth; no DNA synthesis. (2n)
-S = synthesis phase; DNA and centrosomes double. (2n-4n)
-G2 = gap 2 phase preceding mitosis; no DNA synthesis; DNA is checked to ensure
replication is complete. (4n)
*Note: G0, a phase of “terminal” differentiation, is considered to be outside the cell cycle.
b) Mitosis (M phase)
Mitosis is divided into 5 stages:
1) Prophase- mitotic spindle begins to form, and chromosomes condense so that sister
chromatids are attached at the centromere.
2) Prometaphase- the nuclear envelope disassembles, and chromosomes attach to spindle
apparatus via kinetochores.
3) Metaphase- chromosomes migrate to align centrally on the metaphase plate.
4) Anaphasea) A- sister chromatids separate and move towards the pole.
b) B- two spindle poles move apart. Cytokinesis begins.
(see diagram on next page)
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5) Telophase- nuclear envelope reforms, chromosomes decondense, and cytokinesis is
completed.
Stage
Interphase
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
Mitosis Summary Table
Nuclear
Chromosome
Chromosome
Spindle Apparatus
Envelope
Degradation
Location
Yes
Decondensed
Not formed
Nucleus
Centrosomes
Yes
Condensed
Nucleus
separate
Chromosomes
Disassembles
Condensed
Nucleus/Cytoplasm
attach
No
Condensed
Fully formed
Metaphase plate
K-MTs shorten;
No
Condensed
Spindle poles
Polar MTs elongate
Within reforming
Reassembles Decondensing
Disassembling
nuclear envelope
*MTs=microtubules (K-MTs= kinetochore microtubules
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Chromosomal Abnormalities Research
Grade 10 Biology
The goal of this assignment is to give you the opportunity to learn about chromosomal
disorders in humans. Your knowledge gained from this will allow you to understand the
cell cycle and our significance in understanding it.
Directions
Each group of two will pick ONE chromosomal disorder from the list below.
-Down’s Syndrome
-Trisomies 13 and 18
-Turner Syndrome
-Triple X
-Klinefelter Syndrome
-XYY
Research your particular chromosomal abnormality with these questions in mind.
-What causes the particular abnormality you have chosen within the
chromosomes and where does it take place within the cell cycle?
-How are the particular chromosomes affected by the mutation?
-How is the human affected by the chromosomal abnormality and what is a
typical lifespan?
-How likely is a person to be born with this particular chromosomal abnormality?
-Is there any known “fix” for the particular abnormality?
Use some of these websites to get started with your research. The internet is a
great place to start. Remember to post your resources on your powerpoint or on
your poster.
-http://www.marchofdimes.com/professionals/14332_1209.asp
-http://www.pregnancy-info.net/chromosomal_abnormalities.html
-http://anthro.palomar.edu/abnormal/abnormal_4.htm
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Lab Practical
Short Answer Section
Briefly describe what is occurring at each stage of the mitotic division on the left hand
side of the page. Use the lines provided to write your answer.
Prophase
_______________________________________________
_______________________________________________
_______________________________________________
Metaphase
_______________________________________________
_______________________________________________
_______________________________________________
Anaphase
_______________________________________________
_______________________________________________
_______________________________________________
Telophase
_______________________________________________
_______________________________________________
_______________________________________________
Cytokinesis
_______________________________________________
_______________________________________________
_______________________________________________
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Meiosis/Mitosis Test
I. Multiple Choice Section
Circle the letter that matches the correct answer.
1. Which phase of mitosis does this image represent?
A. telophase
B. interphase
C. anaphase
D. metaphase
2. During which phase do spindle fibers form?
A.
B.
C.
D.
Prophase
Metaphase
Telophase
Anaphase
3. During this phase of mitosis, spindle fibers form on opposite ends of the cell,
the nuclear membrane breaks down, and the chromatin condenses.
A. Interphase
B. Telophase
C. Anaphase
D. Prophase
4. During this phase of mitosis, chromosomes align in the center of the cell with
spindle fibers attached to the centromeres.
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A.
B.
C.
D.
Prophase
Metaphase
Anaphase
Telophase
5. Which of the following statements regarding mitosis is NOT true?
A.
B.
C.
D.
Mitosis produces two, genetically identical daughter cells.
Only plant cells undergo mitosis
The daughter cells can also undergo mitotic division.
There are two copies of chromosomes during mitotic division.
6. Cytokinesis is the process by which a cell...
A.
B.
C.
D.
breaks down its nuclear membrane using enzymes.
forms cytokines within the cells.
attaches its spindle fiber to the centromere of the chromosome
divides its cytoplasm and forms two new cells
7. Chromatin is:
A. The substance that binds DNA together
B. DNA and protein complex that makes up chromosomes
C. An enzyme that breaks down the chromosomes after replication
D. The inside lining of a cells nucleus that contains the chromosomes
8. The place where spindle fibers attach to the two conjoining chromatids is
called...
A.
B.
C.
D.
Chromosome
Ligand
Centromere
nitrogenous base
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II. Matching Section
Match each letter to the phrase that corresponds to the appropriate phase of mitosis.
a. interphase
b. prophase
c. metaphase
d. anaphase
e. telophase
f. cytokinesis
1. _____Chromosomes are aligned at the center of the cell by the spindle fibers.
2. _____Spindle fibers shorten, pulling the chromatids apart toward the poles of the cell.
3. _____The longest period of the cell cycle where DNA is replicated, centrioles divide,
and proteins are synthesized
4. _____The chromatin condenses into chromosomes. Microtubules disassemble and
prepare to form spindles in the mitotic division.
5. _____ The chromatids arrive at the poles of the cell and the spindles disassemble.
III. Essay Questions
Write approximately one paragraph for the following essay question. Remember
answer each part of the question thoroughly.
DNA replication is a very complex and fragile process and can easily be disrupted,
causing mutation. Explain one mutation regarding chromosomes that we discussed in
class and its implication.
Reference Sheet
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1) "Labelled Animal Cell." Web. 5 May 2010.
http://wikieducator.org/images/0/02/Labelled_Animal_Cell_worksheet.JPG
2) Goodwin, Nadia. Mitosis Handout. Ross’s Histology, 4 Ed. (pp. 60-62; 68-69). Web. 5 May
2010. <http://cpmcnet.columbia.edu/student/ssn/histology/mitosis_handout03.doc>
3) "YouTube - Mitosis." YouTube - Broadcast Yourself. Web. 5 May 2010.
<http://www.youtube.com/watch?v=VlN7K1-9QB0>