High School Biology : Cell Division

Study concepts, example questions & explanations for High School Biology

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Example Questions

Example Question #101 : Cell Division

An actin filament ring has formed and is tightening around the cell, creating a cleavage furrow. The nuclear membrane has reformed around sister chromatids, which have unwound into chromatin. What stage of the cell cycle is occurring at this point?

Possible Answers:

Anaphase

Interphase

Metaphase

Cytokinesis

S phase

Correct answer:

Cytokinesis

Explanation:

The cell is being cleaved into two daughter cells, which occurs during cytokinesis. Sister chromatins separate during anaphase, the nuclear membrane reforms and DNA unwinds during telophase, so the cell has passed those stages leaving only cytokinesis before the daughter cells repeat the process over again. 

Example Question #21 : Understanding Stages Of The Cell Cycle

During which phase of the cell cycle is the genetic material copied?

Possible Answers:

G0 phase

M phase

G2 phase

S phase

G1 phase

Correct answer:

S phase

Explanation:

The "S" in S phase is short for synthesis, as in DNA synthesis. During this time, each of the organism's chromosomes is copied in order to prepare for cell division so that both daughter cells have the genetic information necessary to be able to function properly. This type of cell division occurs in both somatic, or body, cells and sex cells, but not in prokaryotic organisms.

Example Question #251 : Cell Biology

What is the first phase of mitosis?

Possible Answers:

Cytokinesis

Prophase

Telophase

Anaphase

Metaphase

Correct answer:

Prophase

Explanation:

Mitosis begins with prophase, where the chromatin in the cell condenses into chromosomes. Prophase is followed by metaphase, characterized by the lining up of chromosomes along the metaphase plate. Anaphase is the next stage that begins with the separation of paired chromosomes (sister chromatids). The last stage of mitosis is the telophase, where the chromosomes are cordoned off into new nuclei and return to chromatin form. An easy way to remember this order is to use the acronym PMAT.

Note: Cytokinesis is not technically a part of mitosis, but it is often included. It is an event that directly follows mitosis in which the cytoplasm is divided into two daughter cells. 

Example Question #21 : The Cell Cycle

In which phase of the cell cycle do spindle fibers shorten?

Possible Answers:

Prophase

Anaphase

S phase

Metaphase

G1

Correct answer:

Anaphase

Explanation:

During anaphase, chromosomes are split and sister chromatids move to opposite ends of the cell. This separation is caused by the shortening of a pair of spindle fibers attached to the kinetochore of each sister chromatid. The other end of the spindle fibers is attached to a centriole at each respective end of the cell, which pulls the sister chromatids apart as it shortens the fiber.

Example Question #22 : The Cell Cycle

During which stages of the cell cycle and cell division is DNA completely (for the duration of the stage) condensed into chromosomes? 

Possible Answers:

Anaphase, telophase, and cytokinesis

Metaphase and anaphase

S phase only

Prophase, metaphase, anaphase, telophase, and cytokinesis

G1, S, and G1

Correct answer:

Metaphase and anaphase

Explanation:

It is during prophase that DNA condenses from chromatin into chromosomes, and it is during telophase that DNA unwinds from chromosomes back into chromatin. So for every stage between these two DNA is in chromosome form. The only stages between prophase and telophase are metaphase and anaphase. In all other stages DNA is in chromatin form. 

Example Question #21 : The Cell Cycle

In which of the following stages of the cell cycle are chromosomes pulled apart to opposite poles of the cell?

Possible Answers:

Telophase

Prophase

Metaphase

Interphase

Anaphase

Correct answer:

Anaphase

Explanation:

Anaphase is when the chromosomes are pulled apart. An easy way to remember the phases of the cell cycle is by memorizing IP-MAT.

Interphase
Prophase
Metaphase
Anaphase
Telophase

Then remember that the "metaphase plate" is when the chromosomes line up, and right after that is when they are pulled apart, in anaphase.

Example Question #22 : The Cell Cycle

Cell cycle

In the given picture, name and order the phases in the cell cycle, and list one event that occurs in each phase. 

Possible Answers:

A= G1 phase; Cellular components are duplicated
B= Mitosis;
C= G2 phase; Chromosomes are duplicated
D= S phase; Cell double checks duplication work and makes necessary repairs 

A= S phase; Cell double checks duplication work and makes necessary repairs 
B= Mitosis
C= G2 phase; Cellular components are duplicated
D= G1 phase; Chromosomes are duplicated

A= G2 phase; Chromosomes are duplicated
B= Mitosis;
C= G1 phase; Cell double checks duplication work and makes necessary repairs 
D= S phase; Chromosomes are duplicated

A= Mitosis;
B= G1 phase; Cellular components are duplicated
C= G2 phase; Cell double checks duplication work and makes necessary repairs 
D= S phase; Chromosomes are duplicated

A= G1 Phase; The cellular components are duplicated
B= S Phase; Chromosomes are duplicated
C= G2 Phase; Cell double checks duplication work and makes necessary repairs
D= Mitosis

Correct answer:

A= G1 Phase; The cellular components are duplicated
B= S Phase; Chromosomes are duplicated
C= G2 Phase; Cell double checks duplication work and makes necessary repairs
D= Mitosis

Explanation:

Each cell goes through the cell cycle and can be at any point within it. During the G1 phase all the components of the cell are duplicated. The cell size increases as they produce RNA and synthesize proteins, as well as increase the number of organelles. During the S Phase DNA replication begins and chromosomes become replicated. Each chromosome will have two sister chromatids, connected at the kinetochore. In the G2 Phase the cell double checks the duplication work and makes necessary repairs so that mitosis can begin.

Example Question #1 : Understanding Cell Cycle Regulation

During the cell cycle, there are several checkpoints to ensure proper cell growth and division. Which checkpoint ensures that each duplicated chromatid is appropriately attached to cellular machinery in order to segregate properly?

Possible Answers:

Metaphase checkpoint

G2 checkpoint

G1 checkpoint

G0 checkpoint

Correct answer:

Metaphase checkpoint

Explanation:

During mitosis, the metaphase checkpoint ensures that each duplicated chromatid is attached to the spindle apparatus. If the metaphase checkpoint is not satisfied, the cell will not enter anaphase. This checkpoint is essential for preventing aneuploidy, a condition in which there are an abnormal number of chromosomes in a cell.

The G1 checkpoint determines if the cell will enter the S phase to replicate DNA and prepare for cell division. Quiescent cells, cells that do not frequently divide, are often stopped at the G1 checkpoint for long periods. The G2 checkpoint is used to prevent the cell from entering mitosis if there were errors in the replication of DNA during the S phase. Failure to pass the G2 checkpoint can result in apoptosis. There is no G0 checkpoint.

Example Question #21 : The Cell Cycle

Which of the following best describes the two primary purposes of Active S cyclin-CDK phosphorylation in the cell cycle?

Possible Answers:

The prevention of new complexes from forming AND targeting mitotic cyclins for degradation.

The activation of each assembled pre-replication complex AND promoting the expression of enzymes needed for DNA replication.

The activation of each assembled pre-replication complex AND targeting mitotic cyclins for degradation.

The activation of each assembled pre-replication complex AND the prevention of new complexes from forming.

The targeting of mitotic cyclins for degradation AND promoting the expression of enzymes needed for DNA replication.

Correct answer:

The activation of each assembled pre-replication complex AND the prevention of new complexes from forming.

Explanation:

Active S cyclin-CDK phosphorylation in the cell cycle is primarily intended to ensure that each portion of the cell's genome is copied once and only once. Daughter cells that do not copy a complete genome will likely die; however, carrying extra copies of certain genes will also negatively affect daughter cells, and phosphorylation of proteins that make up pre-replication complexes safeguards against this.

Example Question #1 : Understanding Cell Cycle Regulation

Out of all phases in the cell cycle, most cells spend the majority of their life in __________.

Possible Answers:

Interphase

Metaphase

Prophase

Anaphase

Telophase

Correct answer:

Interphase

Explanation:

Cell division, or mitosis, is a rather small portion of a cell's life and includes prophase, metaphase, anaphase and telophase.  The majority of a cell's life is spent in interphase.

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