embryo sac

noun

plural embryo sacs

: the female gametophyte of a flowering plant consisting of a thin-walled sac within the nucellus that contains the egg nucleus and two polar nuclei which give rise to the endosperm on fertilization

Pollination involves the processes of pollen capture by the stigma, hydration, and pollen tube growth … to place the sperm cells they carry in the embryo sac in the ovule.

—L. C. Sanders and E. M. Lord

Word History

First Known Use

1837, in the meaning defined above

Kids Definition

embryo sac

noun

: the individual that produces female germ cells in the sexually reproducing generation of a flowering plant and that consists of a thin-walled sac containing the egg nucleus and other nuclei which form tissue used for food upon fertilization