X ... XENOTIME
XENOTRANSPLANT ... XXX
XXXI ... XYY
Y ... YARDAGE
YARDARM ... YELLOW BERRY
YELLOW BILE ... YELLOW SEA
YELLOW SPINY DAISY ... YEMEN
YEMENI ... YOKO ONO
YOKOHAMA ... YUCCA WHIPPLEI
YUCKY ... YVES TANGUY
Z ... ZEA SACCHARATA
ZEAL ... ZIGADENE
ZIGADENUS ... ZN
ZOANTHROPY ... ZOYSIA
ZOYSIA JAPONICA ... ZYRIAN
X CHROMOSOME
X RAY
X-AXIS
X-LINKED
X-LINKED DOMINANT INHERITANCE
X-LINKED GENE
X-LINKED RECESSIVE INHERITANCE
X-LINKED SCID
X-OR CIRCUIT