zygote

n. a fertilized egg, or ovum, with a diploid set of chromosomes, half contributed by the mother and half by the father. The zygote divides to become an embryo, which continues to divide as it develops and differentiates—in humans eventually forming a fetus. —zygotic adj.

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Psychology term of the day

July 27th 2024

primary insomnia

in DSM–IV–TR, a sleep disorder characterized by difficulty in initiating or maintaining a restorative sleep to a degree in which the severity and persistence of the sleep disturbance causes clinically significant distress, impairment in a significant area of functioning, or both. The disorder is not caused by a general medical condition or the effects of a substance and is not exclusively an aspect of another sleep disorder or mental disorder. It is termed insomnia disorder in DSM–5. See dyssomnia. Compare primary hypersomnia.