Some scientists want to apply the methods used in cloning animals to produce skin, organs, and other body parts for humans. One of these methods involves taking adult cells from the brain or blood and growing them into new tissues. Another, more complex, technique takes embryo cells and develops them into a wide variety of cell types and tissues. It is this planned use of human embryos that has resulted in controversy and criticism.

一些科学家想用克隆动物的方法，来为人类制造人类使用的皮肤、器官与其它的身体构造。其方法之一是从脑内或血液中提取成熟细胞，把它们培养成新组织。另外一种较为复杂的技术，则是把胚胎细胞培养成各式各样的细胞种类及组织。正是这个有计划的使用人类胚胎引起了争议与批评。

(短文节选,本篇始于：克隆一个你？)