Pollen mother cell ( pmc ) in angiosperms and gymnosperms , a somatic cell that gives rise to four haploid pollen grains by meiosis 花粉母细胞（ pmc ） ：指在被子植物和裸子植物中，能通过减数分裂产生4个单倍体花粉粒的体细胞。
The carpel is homologous with the megasporophylls of certain spore - bearing vascular plants ( pteridophytes ) and the ovuliferous scales of gymnosperms 心皮和能产生孢子的维管植物（羊齿类）还有具胚珠的裸子植物的大孢子叶是同源的。
Gymnosperms lack endosperm and the precise double fertilization characteristic of the angiosperms , although some show a primitive form of it 尽管裸子植物还保留有某些被子植物的基本形态，但它没有被子植物所特有的胚乳以及双受精现象。
They differ from conifers and other gymnosperms by having the ovule enclosed within an ovary , which after fertilization develops into a fruit 被子植物不同于针叶植物和其他的裸子植物，被子植物的胚珠由子房所包被，受精后直接发育为果实。
In the clubmosses and horsetails only one type of strobilus is formed , while in the gymnosperms female megastrobili and male microstrobili both develop 石松和楔叶类只形成一种类型的球果，然而裸子植物既有雌性的大孢子叶球也有雄性的小孢子叶球。
In many gymnosperms the nuclei divide within the pollen grain to produce a small number of cells ( 2 - 40 depending on the group ) representing the male prothallus 在许多裸子植物中，细胞核在花粉粒中分裂以产生少量的细胞（ 2 40个，取决于不同种类） ，代表雄性原叶体。
Albuminous cell 1 . a vertically elongated parenchyma cell , found in groups in the rays of the secondary phloem in gymnosperms , where they are associated with sieve cells 蛋白质细胞： 1 .在裸子植物的次生韧皮部薄壁组织和韧皮射线中发现的1种垂直伸长的细胞，通常与筛胞相结合。
Till today there is no report on molecular evolution of 5s rdna in pinus . thus , the rdna variation pattern and organization in gymnosperm genomes are the primary focus of the present project 8s - 26srdna位点数平均较被子植物多， 5srdna除pinusradiata外，在其它种里则与被子植物相似。
Strobilus ( pl . strobili ) a group of sporophylls ( spore - bearing leaves ) arranged around a central axis , found in gymnosperms , lycophyta ( clubmosses ) , and sphenophyta ( horsetails ) 球果：孢子叶向中轴聚拢形成的结构，存在于裸子植物门植物、石松亚门植物（石松）和木贼纲植物中（楔叶类） 。
He also observed that gymnosperm ovules were not enclosed in an ovary wall , leading to the establishment of one of the basic differences between angiosperms and gymnosperms 他还观察到裸子植物的胚珠并不是被子房壁包围，这个发现直接导致了被子植物和裸子植物之间最根本的几点区别的建立。
