基因内区的英文：
intron

What is the minimum number of transesterification reactions needed to splice an intron from an mRNA transcript? Why?
酯基转移反应从一个mRNA转录来拼接一个内含子的最小数目是多少？

The introns are cut out by processing enzymes in the nucleus and the exons(coding sequences)ligated together
核内的加工酶切下内含子，同时外显子(编码序列)连接在一起。