What meiotic process, relative to the number of chromosomes of a given species, accounts for a significant amount of genetic variation in gametes?

The pachytene stage of the prophase I in the meiosis I division, the process of recombination occurs. The recombination is the process of exchange of gentic material of the same allele between the sister chromatids.

As the recombination result in the exchange of genetic material between sister chromatids, this result in the genetic variations in the progeny.

So, in meiosis 1 the recombination at the pachytene stage of prophase 1 causes a significant amount of genetic variation.

more words for this could be abiotic and biotic

abiotic: living organisms within an ecosystem

biotic: non-living organisms within an ecosystem