Final answer:
The event where a chromosome fails to attach to a spindle fiber during prometaphase refers to an essential step of mitotic spindle fiber attachment to kinetochores in mitosis(a).
Step-by-step explanation:
The question pertains to the event during prometaphase when one of the chromosomes fails to attach to a spindle fiber. The attachment of mitotic spindle fibers to kinetochores is indeed a characteristic event of prometaphase in cell division. Specifically, this step is critical for the proper separation of chromosomes during mitosis(a). If a spindle fiber does not attach to a chromosome, it can lead to problems such as unequal distribution of chromosomes to the daughter cells, potentially causing disorders in the organism.
In the context of meiosis, this event is referred to as prometaphase I and it involves the attachment of spindle fibers to the kinetochore proteins at the centromeres. Meiosis is a special type of cell division that reduces the chromosome number by half, creating four haploid cells, each genetically distinct from the parent cell and from each other.