Dyad: The word “dyad” comes from the Greek “dyas” meaning the number two.
In psychology, a dyad refers to a pair of persons in an interactional situation. For example, a patient and therapist, a woman and her husband, a girl and her stepfather, etc.
In chemistry, a dyad is a bivalent element. And in biology, a dyad is a double chromosome resulting from the splitting of a tetrad (a quadruple chromosome) during meiosis (germ cell formation).
Dynein: A family of microtubule motor proteins that derive energy from ATP (adenosine triphosphatase) activity. The dyneins also form arms on the outer tubules of cilia and flagella. The dynein motor, a cellular complex believed to be composed of 12 distinct protein parts, performs fundamental transportation tasks critical to the cell. Defects in its structure […]
Dys-: Prefix denoting bad or difficult, as in dyspepsia (difficult digestion).
Dysarthria: Speech that is characteristically slurred, slow, and difficult to understand. A person with dysarthria may also have problems controlling the pitch, loudness, rhythm, and voice qualities of his or her speech. Dysarthria is caused by paralysis, weakness, or inability to coordinate the muscles of the mouth. Dysarthria can occur as a developmental disability. It […]
Dyscalculia: A specific developmental disability that affects a person’s ability to conceptualize and perform mathematics. Mild cases can often be compensated for with use of a calculator, but those with severe dyscalculia need special education services.
Dyscrasia: Any disease condition, especially in hematology, as in “blood dyscrasias.” The term “dyscrasia” was borrowed from the Greek meaning “a bad mixture” referring to the ancient belief that an imbalance between the four humors – blood, phlegm, yellow bile, and black bile- which caused disease.