Final answer:
The likely outcome of severing one of the microtubules attached to a chromosome during metaphase is Metaphase arrest, as the cell cycle is halted until chromosomes are correctly aligned and attached for proper segregation. Option number C is correct .
Step-by-step explanation:
If a chromosome is attached to two microtubules from opposite poles and one of the microtubules is experimentally severed, the most likely outcome is Metaphase arrest. During prometaphase, mitotic spindle microtubules attach to each sister chromatid at the kinetochore. Normally, in anaphase, the connection between the sister chromatids breaks down, and the microtubules pull the chromosomes toward opposite poles. In this scenario, if one microtubule is cut, the balanced tension that holds the chromosome at the metaphase plate is disrupted.
Because the chromosomes must be properly aligned and attached to microtubules from both poles to progress to anaphase, the severing of one microtubule would prevent the onset of anaphase and lead to a Metaphase arrest, stopping the cell cycle until the issue is resolved to ensure that daughter cells receive the correct number of chromosomes.