What could cause a cell to be arrested at metaphase?

What could cause a cell to be arrested at metaphase?

• A. A mutation preventing protein degradation
• B. Inactivation of the APC ubiquitin ligase
• C. Improper attachment of chromosomes
• D. All of the above

Answer: (D)

Cellular arrest at metaphase can occur due to a variety of factors that impact the proper progression through the cell cycle. Each of these factors contributes to a failure in advancing to the next stage, thus causing the cell to remain in metaphase. A crucial point in the cell cycle is the transition from metaphase to anaphase, which is regulated by the Anaphase Promoting Complex (APC). The APC is responsible for marking certain proteins for degradation, which is necessary for the separation of sister chromatids. If there is a mutation that prevents protein degradation, it can interfere with the timely progression past metaphase, allowing the cell to remain in this phase. In addition, inactivation of the APC ubiquitin ligase directly affects the cell's ability to progress from metaphase to anaphase. Without the APC functioning properly, proteins that are essential for the separation of chromatids are not degraded, thus sustaining the state of metaphase. Furthermore, if chromosomes are improperly attached to the mitotic spindle, this can also result in the cell being arrested at metaphase. The spindle assembly checkpoint (SAC) monitors the attachment of chromosomes to the spindle apparatus, and if there are errors, the checkpoint prevents the cell from progressing to anaph

Cellular arrest at metaphase can occur due to a variety of factors that impact the proper progression through the cell cycle. Each of these factors contributes to a failure in advancing to the next stage, thus causing the cell to remain in metaphase.

A crucial point in the cell cycle is the transition from metaphase to anaphase, which is regulated by the Anaphase Promoting Complex (APC). The APC is responsible for marking certain proteins for degradation, which is necessary for the separation of sister chromatids. If there is a mutation that prevents protein degradation, it can interfere with the timely progression past metaphase, allowing the cell to remain in this phase.

In addition, inactivation of the APC ubiquitin ligase directly affects the cell's ability to progress from metaphase to anaphase. Without the APC functioning properly, proteins that are essential for the separation of chromatids are not degraded, thus sustaining the state of metaphase.

Furthermore, if chromosomes are improperly attached to the mitotic spindle, this can also result in the cell being arrested at metaphase. The spindle assembly checkpoint (SAC) monitors the attachment of chromosomes to the spindle apparatus, and if there are errors, the checkpoint prevents the cell from progressing to anaph