定点突变
参考答案:
在基因的特定位点引入突变,即通过添加、插入或删除已知的DNA序列中特定的核苷酸序列。
根据句意及首字母提示填空。
1. Many students' favorite subject is s_____.
2. W_____ is the fourth day of a week.
3. Please give me an e_____; I am not clear about the problem.
4. Are your teachers s_____ with you m your lessons?
5. I'm s_____ you will do better in your lessons this term.
对α受体几乎无作用的是
A.去甲肾上腺素
B.可乐定
C.左旋多巴
D.肾上腺素
E.异丙肾上腺素