查询词典 polyad

Barley seeds were irradiated with five different doses of 60 Co-γ ray.There were many kinds of chromosome aberration in pollen mother cells,such as bridge,laggards in anaphase I and anaphase II,asymmetrical division in anaphase I and asynchronous division in anaphase II,ring quadrivalent in metaphase I,three pole division and micro-nuclei in telophase I,micro-nuclei in tetrad and some micro-nucleus separates from the tetrad to form polyad.

大麦种子经5种不同剂量γ射线辐照后， M1植株的花粉母细胞出现多种染色体畸变类型，例如后Ⅰ、后Ⅱ中出现桥、落后，后Ⅰ中出现不对称分裂，后Ⅱ中出现不同步分裂，中期Ⅰ出现环状四价体，末期Ⅰ中有三极分裂和微核，四分体中出现微核且有的微核独立于四分体，从而形成多分体。

Results showed that the PMC meiosis of autotetraploid was similar to the diploid except some particularities. In metaphase Ⅰ, multivalent, quadrivalent, trivalent, bivalent and univalent were observed and some of the chromosomes were found not to rank on the metaphase plate and so did in metaphase Ⅱ cells. In anaphase Ⅰ and anaphase Ⅱ cells, there were lagging chromosomes, chromosome bridge and fragment. During anaphase Ⅱ and telophase Ⅱ, chromosome segregation was not synchronous or equal. At tetrad stage, dyad, triad, tetrad with micronucleus and polyad appeared.

结果表明，同源四倍体花粉母细胞减数分裂过程与二倍体相比，中期Ⅰ染色体构型复杂，有多价体、四价体、三价体、二价体和单价体；中期Ⅰ及中期Ⅱ有部分染色体没有排列在赤道板上；后期Ⅰ及后期Ⅱ出现落后染色体、染色体桥及断片；后期Ⅱ和末期Ⅱ有染色体不同步分离及不等分裂的现象；四分体时期还出现二分体、三分体、含微核的异常四分体及多分体。

Laggard chromosomes were obser ved in anaphase I and anaphase II Polyad had micronuclei.

结果表明普通小麦和华山新麦草的染色体组间不存在同源或部分同源性。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。