A sex chromosome in certain animals, such as chickens, turkeys, and moths. In humans, males are XY and females XX, but in animals with a Z chromosome, males are ZZ and females are WZ.

Zeta-chain-associated protein kinase 70. A member of the protein tyrosine kinase family, ZAP-70 is normally expressed in T cells and natural killer cells and has a critical role in the initiation of T-cell signaling. ZAP-70 is expressed in T cells and tumors of T-cell lineage. A high level of ZAP-70 expression appears restricted to T-cell […]

‘When you hear hoof beats, think of horses, not zebras.’ For example, when someone develops a mild transient cough, a virus infection is the most logical and likely cause, and tuberculosis is a zebra.

A gene that is lethal (fatal) for the zygote, the cell formed by the union of a sperm (male sex cell) and an ovum (female sex cell). The zygote would normally develop into an embryo, as instructed by the genetic material within the unified cell. However, a zygotic lethal gene scotches prenatal development at its […]

A technique in which a woman’s egg is fertilized outside the body, then implanted in one of her fallopian tubes. This technique is one of the methods used to overcome infertility, the inability of couples to produce offspring on their own. First, the egg and the male sperm needed to fertilize it are harvested. Then […]

Yeast infection of the mouth and throat caused by a fungus formerly called Monilia, now known as Candida albicans. This infection is also known as thrush. Yeast organisms are part of the germs normally found in various parts of the body. They ordinarily do not cause any symptoms. Certain conditions, such as antibiotic use, can […]

615, 1963). For related information, see Jaundice.

The solid matter that is discharged in a bowel movement.

Disease of the hypo’glossal nerve. Paralysis of the hypoglossal nerve affects the tongue, making speech sound thick and causing the tongue to deviate toward the paralyzed side. In time, the tongue diminishes in size ‘(atrophies).

Referring to the macrobiota, a region’s living organisms that are large enough to be seen with the naked eye.