How do Cells Ensure Proper Chromosome Segregation During Cell Division?

How do cells ensure proper chromosome segregation during cell division?

A cell has detected a problem: one of its chromosomes is not properly attached to a spindle fiber. The cell is at which checkpoint in the cell cycle? 1) G2 checkpoint 2) S checkpoint 3) M checkpoint 4) G1 checkpoint

Answer:

The cell is at the M checkpoint, which assesses correct attachment of chromatids to spindle fibers to ensure proper chromosome segregation during cell division.

The cell is at the M checkpoint in the cell cycle when it detects a chromosome that is not properly attached to a spindle fiber. This checkpoint assesses the attachment of each kinetochore to a spindle fiber to ensure correct alignment of sister chromatids before proceeding to anaphase, which is an irreversible step. Hence, the M checkpoint, also known as the spindle checkpoint, plays a crucial role in maintaining genetic stability during cell division.

The M checkpoint, also known as the spindle checkpoint, occurs near the end of the metaphase stage of mitosis. It assesses whether all the sister chromatids are correctly attached to the spindle microtubules. If the kinetochores of each pair of sister chromatids are not firmly anchored to at least two spindle fibers arising from opposite poles of the cell, the cycle will not proceed until the attachment is corrected.