Related by context. Frequent words. (Click for all words.) 63 oocytes 63 embryos 62 oocyte 61 fertilized eggs 59 embryo 59 sperm 57 ovary 56 ovarian tissue 55 stem cells 55 ovaries 54 eggs 54 cloned embryos 53 ova 53 germ cells 53 Embryos 52 embryonic cells 52 fertilized egg 51 human embryos 51 follicles 50 blastocyst 50 sperms 50 ES cells 50 Embryo 50 endometrium 49 somatic cell nuclear 49 donor sperm 49 neural stem cells 49 embryonic stem cells 49 pluripotent stem cells 49 fetal tissue 49 blastocysts 49 bone marrow stem cells 49 islet cells 48 stem cells derived 48 pluripotent 48 fertilized 48 meiosis 47 egg 47 testes 47 hematopoietic stem cells 47 frozen embryos 47 SCNT 47 adult stem cells 47 Adult stem cells 47 iPS cells 47 umbilical cords 47 insulin producing 46 ovulate 46 Sperm 46 fertilization 46 amniotic fluid 46 induced pluripotent stem cells 46 genetically identical 46 pancreatic cells 45 parthenogenesis 45 tissue 45 umbilical cord blood 45 cryopreservation 45 destroying embryos 45 infertile 45 stem cell 44 therapeutic cloning 44 sperm donors 44 tissues 44 C. elegans 44 retinal cells 44 offspring 43 vitro fertilization IVF 43 Cord blood 43 zebrafish 43 vitro fertilization 43 chromosomes 43 embryonic 43 placentas 43 ovarian 43 artificially inseminated 43 cells 43 eggs hatch 43 reproductive organs 43 fertility treatments 43 flower buds 43 hESCs 43 tissue samples 43 fatty tissue 43 rhizomes 43 NK cells 42 hormone estrogen 42 mating 42 fertilizing 42 cultured cells 42 infertility treatments 42 thymus 42 wombs 42 mammalian cells 42 adipose tissue 42 hormone 42 uterus 42 hepatocytes 42 fibroblasts 42 genetically engineered mice 42 hatchling