two-cell embryo, mitosis under microscope 3d cells dividing, cell cloning

background biotechnology blastocyst cancer cell cells cleavage clone cloning diploid dividing division egg embryo embryogenesis embryology fertility fertilization gamete genes genetic health human illustration immune immunity insemination magnification medical microscope microscopic mitosis molecular multiplication natural nucleus oocyte organism ovum procreation protein rendering reproduction reproductive research science stem structure twocell under zygote