分体

The megaspore mother cell is located at the 3rd or 4th layer of cells in the nucellus top end. It divides transversally to form a linear megaspore tetrad, and the megaspore at the chalazal end develops into the embryo sac mother cell.

大孢子母细胞位在珠心顶表皮下第三或四层细胞处，经横分裂后产生一直线形的大孢子四分体，其中位居合点端的大孢子发育成胚囊母细胞。

Under the same environmental conditions when the meiosis of microspore mother cell develop into tetrads the female buds were dipped duly with colchicine solution, which guaranteed that chromosome doubling of megaspore in white poplar could be accomplished in a short time. So much workload was cut down, and induction efficiency of triploid white poplars was also improved.

当相同生境以及培养条件下的小孢子母细胞减数分裂达到四分体后，适时采用秋水碱溶液对雌花芽进行浸泡处理，可保证白杨大孢子染色体加倍处理能集中于一个较短的时间段内进行，从而大大减轻了工作量，同时提高三倍体诱导效率和效果。

A group of four cells formed as a result of meiosis in a spore mother cell.

四分体：1由孢子母细胞减数分裂产生的一组四个细胞。

The primary sporogenous cells divided into the second sporogenous cells which would turn into microspore mother cells in a microsporangium. The cytokinesis in meiosis of the microspore mother cells was of modified simultaneous type, forming the decussate, isobilateral or T-shaped tetrads.

初生造孢细胞分裂形成次生造孢细胞，次生造孢细胞再转化为小孢子母细胞，小孢子母细胞减数分裂的胞质分裂为修饰性同时型，四分体排列方式为交叉型、对称型或"T"型，成熟花粉粒二细胞型，开花时散出。

There are three types in china:mixed type,separated type and enhancement type.

我国目前采用的主要有3种结构型式：混合组装型、分体组装型和加载组装型。

Many of the embryoids were abnormal , such as monocotyledon and polycotyledon.

部分体胚有畸形的表现，单子叶、多子叶、子叶联合。

Botany A group of four cells, as of spores or pollen grains formed by division of one mother cell.

四分体：四个一组的来自母细胞分裂的细胞，如孢子或花粉粒

Small cell of the mother after the cytoplasm of simultaneous type, tetrad of epidermis, mature pollen of two cell types.

小孢子母细胞减数分裂后胞质分裂为同时型，四分体为四面体型排列，成熟的花粉粒为二细胞型。

Pollen morphology of the Chinese monotypic genus Dichotomanthes and its out-group Prinsepia utilis were investigated from the point of view of pollen development. The SEM observation revealed that there is not any change in morphology and sculpture of pollen grains from the young pollen grain seperated from callose of tetraspore to the mature pollen grain in Dichotomanthes tristaniaecarpa. Only the volume of pollen grain increased with maturity.

从发育的角度研究了中国特有单种属Dichotomanthes Kurz及与其系统学研究有关的外类群Prinsepia utilis的花粉形态，扫描电镜观察显示Dichotomanthes花粉粒自脱离四分体胼胝质膜开始至成熟二核花粉粒不同发育时期，花粉形态和外壁纹饰未见变化，仅花粉体积随成熟度增加而有所增大。

In pachytene the paired homologous chromosomes contract. At this point each chromosome consists of a pair of chromatids and the two associated chromosomes are termed a tetrad.

在粗线期，配对的同源染色体缩短，这时每条染色体包括2个联合的染色体，每个染色体包括1对染色单体，即四分体。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了