By comparison, most genes have only about 10 exons and are 50 thousand base pairs in length.

相对来说，大多数基因有10外显子和50kbp长。

Most of these gene mutations are deletions or duplications of one or more exons, and a small amount are point mutations.

基因突变大多数为或多外显子的缺或重复，小部分是点突变。

Alright, so the dystrophin gene is a huge gene on the X-chromosome, that has 79 exons and is over 2 million base pairs in length.

抗肌萎缩蛋白基因是X染色体上大的基因，含有79外显子，全长超过2000kbp（书上通常缩写为bp，碱基对）。

More base pairs and more exons mean that there are more chances for mistakes during meiosis, which is when the egg or sperm are being created.

更多的碱基对和外显子意味着减数分裂时有更多出错的可能，导致生成X染色体上有错误编码序列的卵细胞或者精子。