 Just prior to meiosis, during mitotic division, spindle fibers attach to the maternal chromosomes, leaving the paternal chromosomes in the cytoplasm.The paternal chromosomes are therefore excluded from nascent eggs, without recombination having typically occurred.In some cases, such as "Pelophylax esculentus", there is also endomeiosis prior to cell division, which means that the maternal chromosomes are duplicated and each egg contains identical pairs of chromosomes.