东北林业大学
考试科目：《分子生物学》 考试时间：120分钟 试卷总分100分
一、Explain the following terms and concepts：（本大题共5小题，每题2.0分，总计10分）
1．C value paradox 2．tRNA charging 3．RNAi 4．Pseudogene 5．Stringent factor
二、choose the correct answer（本大题共14小题，每题1分，共计14分，请将正确的答案写在答题纸上）
1．Charged tRNA carries an amino acid bound to its:
(A) anticodon；(B) 3’ end；(C) 5’ end；(D) Variable loop 2．The trigger for RNA interference （RNAi） is:
（A）double stranded DNA； （B）single stranded RNA； （C）double stranded RNA； （D）DNA-RNA molecules
3．When only glucose is available to E. coli in the culture medium:
（A）cAMP-CAP is bound to the promoter（；B）cAMP-CAP is not bound to the promoter；（C）The repressor is not bound to the operator；（D）The lac operon is turn on 4．Steroid hormones（类固醇激素） are involved on gene regulation in:
（A）prokaryotes；（B）eukaryotes；（C）both；（D）none 5．The effector molecule for the trp operon is
（A）allolactose；（B
）cyclic AMP；（C）tryptophan ；（D）aporepressor 6．Nonsense suppressor mutations occur in DNA coding for:
（A）
mRNA；（B）tRNA； （C）rRNA； （D）microRNA 7．A gene with 6 exons is expected to have:
(A) 5 introns；(B) 6 introns；(C) 7 introns；(D) incertitude
8．Which of the following enzyme(s) can remove or insert supercoil twists into circular DNA?
(A) Topoisomerases；(B) DNA PolⅡ；(C) Spliceosomes；(D) Helicase 9．RNA instability in alkaline solutions is due to?
（A）Adenine；（B）Ribose；（C）Uracil；（D）single strand 10．TFIIS functions to:
（A）Bind Sp1； （B）Phosphorylate TFIIH；（C）Unwind DNA；（D）Stimulate RNA proofreading；（E）Terminates transcription
11．During DNA replication, the 3' -OH of the growing DNA chain attacks which phosphate of an incoming nucleotide?
(A) Alpha；
(B) Beta；(C) Gamma； (D) Delta
