“珠被”造句

某些植物的珠被和珠心细胞形成完全正常的胚.
The cells of the integument and nucellus of some plants form perfectly normal embryos.

大多数被子植物的胚珠有两层珠被, 而裸子植物通常只有一层.
Most angiosperm ovules possess two integuments, while gymnosperms usually have only one.

外种皮:覆盖在种子外部的坚硬干燥的保护层, 由胚珠的珠被发育形成.
Testa The hard dry protective covering of a seed, formed from the integuments of the ovule.

• #珠被