Related by context. Frequent words. (Click for all words.) 72 fertilized egg 71 embryo 68 cloned embryo 66 fertilized embryos 65 embryos 65 fertilized eggs 63 zygote 60 human embryos 60 ovum 59 leftover embryos 59 blastocyst 59 fetus 59 SCNT 58 stem cells 58 gametes 58 unused embryos 58 fetal tissue 57 cloned embryos 57 Embryos 57 ovary 57 oocyte 57 uterus 56 germ cells 56 mouse embryos 56 somatic cell nuclear 56 uterine lining 56 spermatozoa 56 oocytes 55 embryonic cells 55 transplanted organ 55 frozen embryo 55 uterine wall 54 blastocysts 54 fertilization 54 Embryo 53 somatic cells 53 ovaries 53 embryonic stem cells 53 endometrium 52 Adult stem cells 52 thymus gland 52 ovarian tissue 52 ESCs 52 fallopian tube 52 organism 52 islet cells 52 womb 52 destroying embryos 51 neural stem cells 51 tissue 51 hematopoietic stem cells 51 pluripotent stem cells 51 fetu 51 reproductive tract 50 sperm 50 reproductive cloning 50 retinal cells 50 therapeutic cloning 50 sperms 50 HSCs 50 bone marrow stem cells 50 frozen embryos 50 organelle 50 fertilized 50 transgenic animals 50 vitro fertilization 50 progenitor cell 50 pulmonary valve 50 reproductive organs 49 iPSCs 49 parthenogenesis 49 stem cell 49 naturally occurring protein 49 testis 49 adult stem cells 49 Embryonic stem cell 49 hESCs 49 embryonic 49 transgene 49 follicles 49 thymus 49 fatty tissue 49 cell transplantation 49 placenta 49 genetically identical 48 stem cells derived 48 IVF treatment 48 ES cells 48 unborn fetus 48 chloroplasts 48 oligodendrocytes 48 hair follicle 48 viral vector 48 donor sperm 48 aneuploidy 48 pancreatic cells 48 unborn child 48 hair follicles 48 Cord blood 47 epidermis 47 diseased tissue