guinea pig spermatozoa under microscope

acrosome biology blastomere blastula cap cell cells cleavage cross cut detail development element embryo embryogenesis embryology equipment fertilization fetal flagellum guinea head health histology illustration lab male mammalian medical medicine micro microscope microscopic organs pattern permanent photo pig preparation reproductive research science scientific section sex sperm spermatogenesis spermatozoa spermatozoon stage stages structure system zygote