精子发生的

Sometimes, two sperm can fertilise a single egg, but this is only thought to happen in about 1% of human conceptions.

有时，2个精子会与一个卵子结合，但是这种情况的发生被认为仅占人类的1%。

For the disease to occur, a sperm carrying the mutation (50:50 chance) must fertilise an egg carrying the mutation (50:50 chance).

为疾病的发生，精子进行基因突变（ 50：50机会）必须受精鸡蛋进行突变（ 50：50机会）。

This is the time when the sperm should arrive if a fertilization is to occur.

如果受精将要发生的话，这恰恰是精子应该抵达的时候。

Female parthenogenesis in which the embryo contains only maternal chromosomes due to the failure of the sperm to fuse with the egg nucleus.

由于在精子与卵子融合过程中发生失败而使胚胎只包含母染色体的一种单性生殖。

The results are as follows:(1)in testis tissue, the expression of RB gene only was found in spermatocytes and prespermatids of seminiferous tubule of immature mice and spermatids of mature mice, and it was not found in the spermatogonia, spermatognial stem cell and primary metamorphous sperm from both immature and mature mice.

这些结果表明，RB基因在小鼠精子和卵子的发生过程中有着重要作用

The results showed that : 1 During nonbreeding season, the giant panda′s ovary was still rich with large and small follicular oocytes, and the large follicular oocytes could be matured in vitro; 2 The mean diameter of the oocytes was (141±6.7)μm and lots of cortical granules contained in the cytoplasm of oo...

结果表明∶（1）在非繁殖季节，大熊猫卵巢中小腔及大腔卵泡卵母细胞仍较丰富，其大腔卵泡卵母细胞可在体外培养成熟；（2）大熊猫的卵母细胞平均直径为（141±6.7）μm ，其胞质富含卵黄颗粒；（3）自配 PandaI I号获能液（含丙酮酸钠、肾上腺素等）可使大熊猫精子有效获能；（4）大熊猫卵母细胞体外受精后，经培养可观察到第2 极体，有的受精卵开始发生卵裂。

Besides, we found that the 5′ regions of Dnmt1 and Dnmt2 were nearly completely unmethylated in all normal adults, IVF fetuses, sperm and aborted clones.

此外，我们还发现在正常成体牛、体外受精胎儿、精子和克隆流产牛胎儿中， Dnmt1和 Dnmt2基因的5′端几乎均没有发生甲基化。

"In mammal s, the fertilized egg or zygote undergoes cleavage (cell division without cell growth) to form a hollow ball or blastocyst."

在哺乳动物中，卵与精子结合而成受精卵，受精卵发生数次细胞分裂后，形成一个中空球形的囊胚。

"In mammals, the fertilize d egg or zygote undergoes cleavage (cell division without cell growth) to form a hollow ball or blastocyst."

在哺乳动物中，卵与精子结合而成受精卵，受精卵发生数次细胞分裂后，形成一个中空球形的囊胚。

"In mammals, the fertilized egg or zygote undergo es cleavage (cell division without cell growth) to form a hollow ball or blastocyst."

在哺乳动物中，卵与精子结合而成受精卵，受精卵发生数次细胞分裂后，形成一个中空球形的囊胚。

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。