b primary spermatocytes ---diploid (2n)cell duplicate dNA tetraploid cell(4n) division structure e round cell, become largest, 18 um, left the basal layer N: large, round, on different stage of division (the prophase of meiotic division up to 22 days) through first meiosis divides into two secondary spermatocyte(2n, 23X or 23Y)b. primary spermatocytes ---diploid(2n)cell →duplicate DNA → tetraploid cell(4n) →division ---structure: round cell, become largest, 18 um, left the basal layer N: large, round, on different stage of division(the prophase of meiotic division up to 22 days) ---through first meiosis divides into two secondary spermatocyte(2n, 23X or 23Y)