| Y Chromosome |
| Y Chromosome, Human use Chromosomes, Human, Y |
| Y-Box-Binding Protein 1 |
| Y-Linked Genes use Genes, Y-Linked |
| Y-Linked Genetic Diseases use Genetic Diseases, Y-Linked |
| Yaba monkey tumor virus |
| Yaba Virus use Yaba monkey tumor virus |
| YAG Lasers use Lasers, Solid-State |
| Yageine use Harmine |
| Yak use Cattle |
| Yam use Dioscorea |
| Yam Bean, African use Sphenostylis |
| Yam, Pseudo use Ipomoea batatas |
| Yang Deficiency |
| Yang Hsu use Yang Deficiency |
| Yang Xu use Yang Deficiency |
| Yangxu use Yang Deficiency |
| Yarrow use Achillea |
| Yarrowia |
| Yatapoxvirus |
| Yaupon use Ilex vomitoria |
| Yawning |
| Yaws |
| Yazumycins use Streptothricins |
| Yearbooks |
| Years of Life Lost use Potential Years of Life Lost |
| Yeast Artificial Chromosomes use Chromosomes, Artificial, Yeast |
| Yeast Proteins use Fungal Proteins |
| Yeast Two-Hybrid Assay use Two-Hybrid System Techniques |
| Yeast Two-Hybrid System Techniques use Two-Hybrid System Techniques |
| Yeast, Baker's use Saccharomyces cerevisiae |
| Yeast, Brewer's use Saccharomyces cerevisiae |
| Yeast, Budding use Saccharomycetales |
| Yeast, Dried |
| Yeast, Fission use Schizosaccharomyces |
| Yeast, Nutritional use Yeast, Dried |
| Yeasts |
| Yellow Baboon use Papio cynocephalus |
| Yellow Dock use Rumex |
| Yellow Fever |
| Yellow Fever Vaccine |
| Yellow fever virus |
| Yellow Jackets use Wasps |
| Yellow Marrow use Bone Marrow |
| Yellow Nutgrass use Cyperus |
| Yellow-head virus use Roniviridae |
| Yellow-Jessamine use Gelsemium |
| Yellowroot use Xanthorhiza |
| Yemen |
| Yerba buena use Micromeria douglasii |
| Yerba mansa use Anemopsis californica |
| Yerba Mate use Ilex paraguariensis |
| Yerba Santa use Eriodictyon |
| Yersinia |
| Yersinia enterocolitica |
| Yersinia Infections |
| Yersinia pestis |
| Yersinia pseudotuberculosis |
| Yersinia pseudotuberculosis Infections |
| Yersinia rucker |
| yes Proto-Oncogene Protein use Proto-Oncogene Proteins c-yes |
| Yew, Harrington Plum use Cephalotaxus |
| Yin Deficiency |
| Yin Hsu use Yin Deficiency |
| Yin Xu use Yin Deficiency |
| Yin-Yang |
| Yinxu use Yin Deficiency |
| Ylang-Ylang use Cananga |
| YLF Lasers use Lasers, Solid-State |
| Yoga |
| Yoghurt use Yogurt |
| Yogurt |
| Yohimbe use Pausinystalia |
| Yohimbine |
| Yohimbinum |
| Yolk Proteins use Egg Proteins |
| Yolk Proteins, Dietary use Egg Proteins, Dietary |
| Yolk Sac |
| Yolk Sac Tumor use Endodermal Sinus Tumor |
| Young Adult |
| Young Modulus use Elastic Modulus |
| Youth use Adolescent |
| YSGG Lasers use Lasers, Solid-State |
| Ytterbium |
| Yttrium |
| Yttrium Isotopes |
| Yttrium Radioisotopes |
| Yttrium-Lithium-Fluoride Lasers use Lasers, Solid-State |
| Yttrium-Scandium-Gallium Garnet Lasers use Lasers, Solid-State |
| Yucca |
| Yucca filamentosa |
| Yugoslavia |
| Yukon Territory |
| Yumel use Elemuy gauteria |
| YY1 Transcription Factor |
