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combinations of more than two conjugated chromosomes occasionally formed during the maturation of germ cells in the stage of meiosis. Multivalents are found mostly in aneuploid and polyploid organisms; they are very rare in diploids. Trivalents, tetravalents, pentavalents, and higher multivalents are distinguished according to the number of chromosomes. The formation of multivalents usually results in the appearance of germ cells with low viability and organisms with an abnormal chromosome set.