BIOS 1404 Test 3 - –Answer D) chromatids remain attached to one ...

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BIOS 1404 Test 3

• The centromere is a region in which

–Answer

• chromatids remain attached to one another until anaphase.
• At which phase are centrioles beginning to move apart in animal cells?

–Answer

• prophase
• If there are 20 centromeres in a cell at anaphase, how many chromosomes are there in each

daughter cell following cytokinesis?–Answer

• 10
• Where do the microtubules of the spindle originate during mitosis in both plant and animal

cells?–Answer

• centrosome
• Measurements of the amount of DNA per nucleus were taken on a large number of cells

from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle did the nucleus contain 6 picograms of DNA?–Answer

• G2
• What is a cleavage furrow?

–Answer

• a groove in the plasma membrane between daughter nuclei
• Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in

concentration during the cell cycle, are called –Answer cyclins. 1 / 3

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• All cell cycle checkpoints are similar in which way?

–Answer They give the go-ahead signal to progress to the next checkpoint.

• Movement of the chromosomes during anaphase would be most affected by a drug that

–Answer prevents shortening of microtubules.

• If cells in the process of dividing are subjected to colchicine, a drug that interferes with the

formation of the spindle apparatus, which would be the first mitosis stage affected by this –Answer metaphase

• After which checkpoint is the cell first committed to continue the cell cycle through M?

–Answer G1

• Which of the following does not occur during mitosis?

–Answer replication of the DNA

• A particular cell has half as much DNA as some other cells in a mitotically active tissue.

The cell in question is most likely in –Answer G1.

• One difference between cancer cells and normal cells is that cancer cells-

–Answer continue to divide even when they are tightly packed together.

• Which of the following is a protein maintained at constant levels through- out the cell cycle

that requires cyclin to become catalytically active?–Answer Cdk

• Which of the following is a true statement about sexual vs. asexual repro- duction?

–Answer 2 / 3

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In sexual reproduction, individuals transmit 50% of their genes to each of their offspring.

• Eukaryotic sexual life cycles show tremendous variation. Of the following elements,

which do all sexual life cycles have in common?

• Alternation of generations II. Meiosis III. Fertilization IV. Gametes
• Spores

–Answer II, III, and IV

• If a cell has completed the first meiotic division and is just beginning meio- sis II, which of

the following is an appropriate description of its contents?–Answer It has half the amount of DNA as the cell that began meiosis.

• After telophase I of meiosis, the chromosomal makeup of each daughter cell is

–Answer haploid, and the chromosomes are each composed of two chromatids.

• When does the synaptonemal complex disappear?

–Answer late prophase of meiosis I

• Which of the following happens at the conclusion of meiosis I?

–Answer Homolo- gous chromosomes are separated.

• For the following questions, match the key event of meiosis with the stages listed below.

Please draw a pair of sister chromatids and of hologogous chromososmes (holmologs) before answering this question.Prophase I Metaphase I Anaphase I Telophase I V. Prophase II VI. Metaphase II VII. Anaphase II VIII. Telophase II Centromeres of sister chromatids disjoin and chromatids separate.–Answer VII

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