how many pairs of chromosomes are involved in the fertilization of a human egg by a sperm cell
1 In a human egg or sperm, there are 23 chromosomes, one of which is an X or Y. 2  The number of chromosomes is reduced from 46 to 23 during the process of meiosis. 3  Fertilization of the egg by the sperm restores the diploid number of 46 chromosomes. All cells in a higher eukaryote (like us) are diploid Â­ EXCEPT ...for the germ cells Â­ eggs and sperm. 2  Germ cells have only half the number of chromosomes as a diploid cell Â­ one of each pair-and are termed haploid (n) . 3  In a human egg or sperm, there are 23 chromosomes, one of which is an X or Y.