Biology Chapter 12

Last update by mayur on 03/27/2014
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Proteins that are involved in the regulation of the cell

cycle, and that show fluctuations in concentration during thecell cycle, are called

A) ATPases.

B) kinetochores.

C) centrioles.

D) proton pumps.

E) cyclins.



Answer:

E) cyclins.



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    Regarding mitosis and cytokinesis, one difference between higher plants and animals is that in plants?

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    The MPF protein complex turns itself off by 

    A) activating a process that destroys cyclin component. 

    B) activating an enzyme that stimulates cyclin. 

    C) binding to chromatin. 

    D) exiting the cell. 

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    A) activating a process that destroys cyclin component. 



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    A mutation results in a cell that no longer produces a 

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    B) The cell would never leave metaphase. 

    C) The cell would never enter metaphase. 

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    E) The cell would undergo normal mitosis, but fail to enter the next G1 phase.


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    Which of the following is true concerning cancer cells? 

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    Which of the following describe(s) cyclin-dependent kinase (Cdk)? 

    A) Cdk is inactive, or "turned off," in the presence of cyclin. 

    B) Cdk is present throughout the cell cycle. 

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    A particular cyclin called cyclin E forms a complex with a cyclin-dependent kinase called Cdk 2. This complex is important for the progression of the cell from G1 into the S phase of the cell cycle. Which of the following statements is correct? 

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    Cells from an advanced malignant tumor most often have very abnormal chromosomes, and often an abnormal total number of chromosomes. Why might this occur? 

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    C) Chromosomally abnormal cells can still go through cell cycle checkpoints. 

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    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 

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

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