英语语法分析

All nucellar cells disappear, when an embryo sac is ripe.

属薄珠心，胚囊形成时珠心细胞全部消失。

Activation of nucellar cells by discharge from the pollen tubes has been claimed.

认为由花粉管的流出物能使珠心细胞活化。

There are several nucellar cells in micropylar region that develop into embellum.

珠孔区域有伸长的珠心细胞。