pronucleus

The haploid nucleus of a sperm or egg before fusion of the nuclei in fertilization.

A primitive nucleus; the nucleus of an ovum or of a spermatozoön before these have united to form the definitive nucleus of an impregnated ovum.

In botany, the nucleus of a conjugating gamete, which on coalescing with another pronucleus forms the germ-nucleus.

One of the two bodies or nuclei (called male and female pronuclei) which unite to form the first segmentation nucleus of an impregnated ovum.

Either of the two haploid nuclei (of a sperm and ovum) that fuse during fertilization

the nucleus of the ovum or sperm after fertilization but before they fuse to form the nucleus of the zygote