Intro - Cell Cycle Control System (4.2)

Multiple Choice

Which of the following best describes the role of a checkpoint in the cell cycle?

• It is a control point where stop and go-ahead signals regulate the cell cycle.

• It is the location where cells divide rapidly.

• It is the site where DNA is replicated.

• It is the place where cells die.

Open Ended

Why is it important for the cell cycle to have a control system with checkpoints?

Multiple Choice

Which of the following phases is NOT associated with a major cell cycle checkpoint?

• G1 phase

• S phase

• G2 phase

• M phase

Open Ended

Explain the role of checkpoints in the cell cycle and why they are crucial for cellular health.

Fill in the Blank

If a cell does not receive a go-ahead signal at the G1 checkpoint, it exits the cell cycle and enters the ___ phase.

Open Ended

Describe how non-dividing cells, such as mature nerve cells, differ from liver cells in terms of their ability to re-enter the cell cycle.

Multiple Choice

Which condition is NOT checked by the G1 checkpoint before allowing a cell to continue through the cell cycle?

• Adequate cell size

• Presence of growth factors

• Proper chromosome alignment

• No damage to DNA

Multiple Select

Select all statements that correctly describe the G1 checkpoint.

• It checks for DNA damage.

• It ensures the cell has grown to an adequate size.

• It checks for proper chromosome alignment.

• It verifies the presence of growth signals and nutrients.

Multiple Choice

Which checkpoint ensures that all kinetochores are properly attached to microtubules before the cell proceeds to anaphase?

• G1 checkpoint

• G2 checkpoint

• M checkpoint

• S checkpoint

Multiple Select

Which of the following statements about cyclins and CDKs is/are correct?

• CDKs are only activated when bound to cyclins.

• Cyclins are enzymes that phosphorylate other proteins.

• Cyclin-CDK complexes allow cells to pass each checkpoint.

• CDKs are destroyed after activating target proteins.

Open Ended

Explain the role of cyclin-dependent kinases (CDKs) in the regulation of the cell cycle.

Multiple Choice

During which phase of the cell cycle does Cyclin E reach its highest concentration?

• G1 Phase

• S Phase

• G2 Phase

• Mitosis

Fill in the Blank

The presence of ___ causes G1 cyclin concentrations to increase, allowing the cell cycle to pass the G1 checkpoint and divide.

Open Ended

Compare the effect of the presence and absence of G1/S cyclin on the activity of Cdk and the initiation of S phase.

Multiple Choice

Which process stops cell division when cells become too crowded at the G1 checkpoint?

• Density-dependent inhibition

• Apoptosis

• Cell differentiation

• Mitosis

Open Ended

Explain how the G2 checkpoint regulates cell division through both stimulation and inhibition mechanisms.

Multiple Select

Which of the following are possible fates of a cell after receiving specific molecular signals?

• Mitosis and division

• Differentiation

• Apoptosis

• Mutation

Fill in the Blank

Fill in the blank: The process by which cells specialize in structure and function is called ___.

Fill in the Blank

Fill in the blank: Mutations in proto-oncogenes can cause them to become ___, leading to overstimulation of the cell cycle.

Open Ended

What are the two types of genes that regulate the cell cycle and how do mutations in these genes contribute to cancer?

Multiple Choice

Which of the following best explains how mutations in proto-oncogenes and tumor suppressor genes can lead to cancer, as illustrated in the diagram?

• Mutations cause proto-oncogenes to become oncogenes, resulting in too much cell growth (too much gas), and inactivation of tumor suppressor genes removes growth inhibition (no brake), both leading to cancer.

• Mutations in proto-oncogenes slow down cell growth, while tumor suppressor genes speed it up, preventing cancer.

• Proto-oncogenes and tumor suppressor genes have no effect on cell growth or cancer development.

• Mutations in tumor suppressor genes increase the braking effect, stopping cell growth completely.

Open Ended

How do internal and external signals influence the regulation of the cell cycle control system?

Multiple Choice

What is the role of a checkpoint in the cell cycle control system?

• It acts as a control point for stop and go-ahead signals.

• It initiates cell division in all cell types.

• It prevents any cell from dividing.

• It only responds to external signals.