1·Because identical twins come from a single fertilized egg that splits into two, they share virtually the same genetic code.
由于同卵双胞胎来自于一个分裂成两个的受精卵,他们实际上共享相同的遗传密码。
2·Biology has a pretty good understanding of how animals develop from a fertilized egg to a fully formed organism.
生物学对动物是怎么从一个受精卵发展一个完全成形的有机体有一个相当好的理解。