An organism consisting of two or more tissues of different genetic composition , produced as a result of mutation , grafting , or the mixture of cell populations from different zygotes 嵌合体由两种或两种以上有不同基因结构的组织所构成的有机体，由于突变、嫁接或来自不同合子的细胞群体相混合而产生。
Fertilization is a highly programmed process by which two radically different cells , sperm and egg , unite to form a zygol it is mediated by complementary molecules present on the surface of the respective gametes . especially the proteins in the sperm acrom play an important role , but only a little can be extracted from sperm . now large amount of proteins can be obtained easily using biological technique 受精是配子间相互作用最后融合成合子的过程，是由配子各自表面蛋白分子互补介导的，特别是存在于精子顶体的蛋白，但从精子中提取量少，用分子生物学手段大量克隆表达所需蛋白为受精机理的研究提供了方便。
