X - Chromosome X. Chromosome that in mammals determines the formation of female sexual characteristics. For the formation of females you need pair XX. (see Y).
Xanthophyll - Yellow pigment that occurs in plants, a member of the carotenoid group.
Xerophytmia - Process of dryness and ulceration of the transparent cornea of the eye, usually caused by lack of vitamin A, which can lead to partial or total blindness.
Xylem - Or wood. Tissue responsible for conducting the raw sap of tracheophyte plants.
Y - Y chromosome. Chromosome that in mammals determines the formation of male sexual characteristics. For male training you need pair XY. (see X)
Zygote - Egg or zygote is the name of the cell formed after the fusion of male gametes. See cardiogram.
Zooplankton - a group of animals, usually microscopic, that float in aquatic ecosystems and which, although they have their own movements, are not able to overcome the currents.
Zonula adherens - See intermediate junction.
Zonula occludens - See narrow junction.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z