Many people object to experimentation on embryos.
许多人反对用胚胎做实验。
There are 24,000 frozen embryos in clinics across the country.
全国各地的诊所里有24000个冷冻胚胎。
Early embryos of many species develop ancestral features.
许多物种的早期胚胎具有其祖先的特性。
If it is cut in a plane different from the one used by the early investigators, it will not form two whole embryos.
如果在一个不同于早期研究人员所使用的平面上切割，就不会形成两个完整的胚胎。
The international trade in semen and embryos from cloned animals created in north and south America and beyond was effectively impossible to police.
在北美，南美以及其他一些地方生产的精子和克隆动物胚胎，其在国际范围内的交易已经无法加以有效监管。
Nearly a century ago, biologists found that if they separated an invertebrate animal embryo into two parts at an early stage of its life, it would survive and develop as two normal embryos.
近一个世纪前，生物学家发现，如果他们在无脊椎动物胚胎生命的早期阶段将其分成两部分，它会存活下来并发育成两个正常的胚胎。
The most successful groups of land plants are those that evolved methods of fertilized sex cell dispersal that are independent of water and structures that protest developing embryos from drying out.
最成功的陆生植物群体是那些进化出了受精性细胞散布方法的群体，这些方法不依赖于水和防止发育中的胚胎干涸的结构。
Studying the fruit fly, a household nuisance but a time-honored experimental subject, has enabled the secrets of how embryos develop to begin to be unraveled by scientists.
果蝇在家中招人讨厌，但却是一个历史悠久的实验对象。通过研究果蝇，科学家们得以揭开胚胎发育的秘密。
Because current federal law already forbids the use of federal funds to create embryos for research or to knowingly endanger an embryo 's life, NBAC will remain silent on embryo research.
因为现今的联邦法律已经禁止使用联邦基金克隆胚胎用于研究或者有意地威胁胚胎的生命，NBAC在胚胎研究上将保持沉默。
The exact number of embryos lost to cryoinjury varies.
冷冻损伤胚胎的确切数目各不相同。
TJP2 is crucial during development as silencing inhibits blastocele formation in mouse embryos.
TJP2 在发育过程中至关重要，因为沉默会抑制小鼠胚胎中的胚泡形成。
But it is active only in embryos.
可是它仅仅在晶胚中才具有活性。
So how might the algae enter the embryos?
那么水藻到底是如何进入胚胎里的呢？
Stem cells were recovered from these embryos.
干细胞就是从这些早期胚胎上得到的。
Have you ever looked at pictures of embryos?
你有没有看过胎儿的照片？
However, all human embryos initially have a tail.
不过，所有的人类胚胎最初都有一根尾巴。
And the embryos bask in the oxygen given off by the algae.
胚胎也因为藻类产生的氧气而受益。
They froze the embryos. A year later, Mr Roman filed for divorce.
于是他们将所有胚胎都冷冻起来，一年之后，罗曼先生提出离婚。
A likely moment occurs as the embryos' nervous systems begin to form.
有可能是在胚胎的神经系统开始形成的时候。
Precisely what doctors are supposed to do with these embryos is unclear.
医生们该拿这些胚胎怎么办，具体事项还不甚明了。
Without syncytin, mice developed deformed placentas, and their embryos died.
没有合胞体蛋白，老鼠的胎盘畸形生长，胚胎死亡。
The protein seems to be especially active while human embryos are developing.
这写蛋白质在人类胚胎发育的时候似乎尤其活跃。
Then they labeled cells in even earlier embryos to track where they wound up.
他们还对更早期的胚胎细胞进行标记跟踪，以确定移植的细胞如何愈合。
At the moment human embryonic stem cells usually come from surplus IVF embryos.
目前，人类的胚胎干细胞通常来自于多余的IVF胚胎。
The only difference is at the chromosomal level, deep inside the embryos' cells.
唯一的区别在于染色体的水平，它埋藏在胚胎细胞的深处。
Five years ago it announced with a fanfare that it had grown cloned human embryos.
五年前，这个公司曾鼓吹其培养了克隆的人类胚胎。
Former Massachusetts Gov. Mitt Romney opposes using embryos from fertility clinics.
前马萨诸塞州州长罗姆尼反对使用从生育诊所得来的胚胎。
But they could not agree on what to do with the three embryos that survived freezing.
但是，双方对如何处理冻存的三个胚胎无法达成一致。
It is caused by a disturbance in a group of cells in embryos called neural crest cells.
这种病是因为一群叫做神经嵴细胞的胚胎细胞出现扰乱所引起的。
It is caused by a disturbance in a group of cells in embryos called neural crest cells.
这种病是因为一群叫做神经嵴细胞的胚胎细胞出现扰乱所引起的。
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