Final answer:
During meiosis, when a pericentric inversion occurs in one homologous chromosome while the other remains normal, an inversion loop is formed to facilitate accurate pairing. This allows proper gene alignment, although it may cause regions of imprecise synapsis. This adaptability minimizes the risk of aneuploid gametes and related genetic consequences.
Step-by-step explanation:
When a pericentric inversion occurs in one homologous chromosome and the other remains normal, the two chromosomes can still undergo meiosis. During this process, the inverted chromosome must form a compensatory loop structure to pair accurately with its non-inverted counterpart. This process is necessary for the chromosomes to line up correctly and allow for proper gene alignment and recombination.
The structure formed is generally referred to as an inversion loop. This loop allows the inverted segments to align with the corresponding segments on the non-inverted homolog so that crossover can occur at the correct location. Without the formation of the inversion loop, genetic material could be mismatched, which might lead to incorrect recombination and potentially harmful mutations or chromosomal abnormalities in the gametes.
The pairing of inverted and non-inverted chromosomes may result in structures like a V formation or a cruciform configuration, which could be observed during the prophase I of meiosis. However, while this adaptive looping allows for gene alignment, it may also lead to stretches in the chromosomes and cause regions of imprecise synapsis, affecting the stability of genetic material during meiotic division.