1·It is easily extracted, because it is one of a handful of genes found outside the cell nucleus, in structures called mitochondria.
它很容易提取，因为它是在细胞核之外、叫做线粒体的结构里被发现的少量基因之一。
2·Erythrocytes in mammals are anucleate when mature, meaning that they lack a cell nucleus.
哺乳动物中的红细胞成熟时是无核的，这意味着它们缺乏细胞核。
3·While, like bacteria, archaeans don't have a cell nucleus, they share other traits with eukaryotes like you and me.
虽然，像细菌一样，古生菌也没有细胞核，但是它们与你我这样的真核生物具有其他共同的特性。
4·We are family: Scientists suspect that a large DNA-based virus took up residence inside a bacterial cell more than a billion years ago to create the first cell nucleus.
病毒跟我们是一家人：科学家认为，十多亿年前一个大的DNA病毒在细菌细胞内居住并形成了第一个细胞核。
5·The scientists extracted a cell nucleus from an organ of a dead mouse and planted it into the egg of another mouse which was alive, leading to the birth of the cloned mouse.
科学家们从死鼠的器官中提取细胞核，移入到另一只活鼠的卵细胞中，最终克隆出了小鼠。