Name: Answer Key
BioSci 93 Discussion Week 6
Online Worksheet 2
1) Which of the following does NOT occur during mitosis?
a. Spindle formation
b. Breakdown of the nuclear membrane
c. Separation of sister chromatids
d. Formation of metaphase plate
e. Replication of DNA
2)
a. This is a diploid (2n) cell. How many chromosomes does it have? 4
b. Draw what this cell looks like in prophase.
c. On your cell above, label the following:
(i)
a chromatid
(ii)
a pair of sister chromatids
(iii)
one chromosome
(iv)
a centromere
d. How many pairs of sister chromatids are in the cell? 4
e. Draw what this cell will look like in the following phases of mitosis, and list at least
two processes that are occurring at each stage.
1 of 3 Prophase
1. Chromatin begins to condense into discrete chromosomes
2. The mitotic spindle begins to form
3. Centrosomes move away from each other towards opposite poles
Metaphase
1. Chromosomes align at the metaphase plate
2. Centrosomes are now at opposite ends of the pole
3. Each sister chromatid of the chromosome has its kinetochore attached to a kinetochore
microtubule
Anaphase
1. The sister chromatids part as the protein holding them together is cleaved
2. Kinetochore microtubules shorten, and chromatids (now considered full chromosomes)
move to opposite poles
3. Cell elongates due to lengthening of non-kinetochore microtubules
f. Draw the resulting daughter cells:
2 of 3 g. How many chromosomes does each daughter cell have? 4
h. Circle one: These cells are (diploid, haploid).
3) Which one is ordered from lowest to highest biological complexity?
a. Chromatin, Chromatid, Chromosome
b. Centrosome, Chromatid, Chromatin
c. Chromosome, Centrosome, Chromatid
4) Which of the following statements about kinetochore microtubules is TRUE?
a. They are composed of carbohydrates and proteins
b. They are found during mitosis but not meiosis
c. They interact with myosin to form the cleavage furrow
d. They are made of tubulin subunits
e. They are found during meiosis but not mitosis
5) The motor protein myosin plays an important role in cell division. Which of the following
correctly identifies the function of this protein and the stage of mitotic division where it is
important?
a. Prophase, replication of the MTOCs
b. Metaphase, alignment of chromosomes at cell equator
c. Cytokinesis, formation of the cleavage furrow
d. Anaphase, movement of chromosomes toward the MTOCs
e. Prophase, movement of the sister chromatids toward metaphase plate
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