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 […]

Cardioplegia: Paralysis of the heart, as may be done electively in stopping the heart during cardiac surgery. Cardioplegia may be done using chemicals, cold (cryocardioplegia), or electrical stimulation.

Dissociation: In psychology and psychiatry, a perceived detachment of the mind from the emotional state or even from the body. Dissociation is characterized by a sense of the world as a dreamlike or unreal place and may be accompanied by poor memory of specific events.

Diphallia: an extremely rare congenital abnormality (birth defect) in which a male infant is born with duplication of the penis. This condition is estimated to occur in only one out of every 5 to 6 million live births. Diphallia is often associated with other abnormalities including gastrointestinal problems and other genitourinary abnormalities. The anatomical abnormality […]

One of the two classes of bases in DNA and RNA. The pyrimidine bases are thymine (T) and cytosine (C) in DNA and cytosine (C) and uracil (U) in RNA.

Limping and/or pain due to inadequate venous drainage, poor return of blood by the veins, from the legs.