ARTWORK, BODY, CELL, CELLULAR, CHROMOSOME, DEVELOPMENT, DIAGRAM, DIVISION, DNA, GAMETE, GAMETES, GAMETOGENESIS, HAPLOID, HUMAN, ILLUSTRATION, INFERTILITY, MALE, MAN, MITOSIS, NO-ONE, NOBODY, NORMAL, PIKOVIT, PROCESS, PRODUCTION, REPLICATION, REPRODUCTION, REPRODUCTIVE, SEMINIFEROUS, SERTOLI, SEXUAL, SPERM, SPERMATID, SPERMATOCYTE, SPERMATOGENESIS, SPERMATOGONIUM, STAGES, STEM, SYSTEM, TUBULE,