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懷孕 |
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人的生命從什麼時候開始？
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我們知道婦女懷孕是由於幾個生物過程導致的結果。這些生物過程是： |
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男女性細胞融合，由此產生一個被稱為合子的單一新細胞。這一過程稱為受精。
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通過細胞分裂，合子生長，產生由許多細胞構成的稱為胚泡的有空腔球形體。這一過程稱為卵裂。
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胚泡附著到子宮內膜。這一過程稱為植入。
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如果伴隨這些過程之一出了差錯，懷孕就不可能發生。
儘管如此，出於科學研究原因，許多發育生物學家傾向於把授精過程一完成定義為懷孕。另一方面，一些生殖生理學家出於自己科學研究的原因，認為一個新生命體開始於植入過程完成之後。對於生殖生理學家來說，除非受精導致了妊娠，不然就無懷孕之說。 |
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Conception |
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When does human life begin?
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We know that a woman's pregnancy results from a combination of several biological processes. Among these are: |
- The union of a male and female sex cell which produces a new single cell called zygote.
This process is called
fertilization.
- The growth of the zygote by cell division, resulting in a hollow ball of cells called
blastocyst. This process is called
segmentation.
- The attachment of the blastocyst to the lining of the uterus. This process is called
implantation.
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If anything goes wrong with even one of these processes, no pregnancy can occur.
Still, for certain scientific reasons many developmental biologists prefer to speak of a conception as soon as the process of fertilization is completed. On the other hand, some reproductive physiologists believe for their own scientific reasons that a new life begins with the process of implantation. For them, no conception occurs unless the fertilization leads to pregnancy. |
