第17题: [单项选择]逆转录病毒基因组复制时所用的引物为() A. RNA B. DNA C. tRNA D. mRNA E. 不需要引物 参考答案:C 答案解析:考点:逆转录酶。逆转录是在逆转录酶的催化下,以RNA为模板、dNTP为底物合成DNA的过程。逆转录酶具有以RNA作模板的dNTP聚合活性和RNase活性。其催化合成反应的方向是5′→3′。需要tRNA
第18题: [单项选择]What will happen to listeners later A. They will be shown an informational chart, B. They will be given medical tests. C. They will be led on a tour of the hospital. D. They will undergo cancer treatment. 参考答案:C