分子生物学（Molecular Biology)答案2023秋

第七章测试

1.Which is NOT a final product of gene expression?（ ）
A:tRNA B:rRNA C:protein D:mRNA
答案:D
2.If a gene is expressed at relatively constant rate in almost all the cells, it is called a(an) （ ）
A:constant gene B:repressible gene C:inducible gene D:housekeeping gene 3.The most efficient step of gene expression regulation is （ ）
A:transcription initiation B:activation of chromosomes C:transcription termination D:translation initiation 4.Which one is NOT a cis-acting element?（ ）
A:enhancer B:activator protein C:promoter D:silencer 5.The prokaryotic operator sequence is usually （ ） .
A:located on the downstream region of promoter B:bound by RNA polymerase C:located on the upstream region of promoter D:bound by CAP 6.In the regulation of lac operon, when the medium contains both glucose and lactose, which statement is true?（ ）
A:repressor is active; CAP is inactive B:both repressor and CAP are inactive C:both repressor and CAP are active D:repressor is inactive; CAP is active 7.In lac operon, repressor protein could bind to( )sequence.（ ）
A:lac I B:lac Z C:promoter D:operator 8.In the regulation of lac operon, when the medium contains only glucose, which statement is true?（ ）
A:concentration of cAMP is high, CAP is inactive B:concentration of cAMP is low, CAP is inactive C:concentration of cAMP is low, CAP is active D:concentration of cAMP is high, CAP is active 9.If a gene is expressed only in certain organs or tissues, this is called （ ）
A:stage specificity of gene expression B:none of the above C:temporal specificity of gene expression D:spatial specificity of gene expression 10. Which is NOT the basal cis-acting elements in eukaryotes?（ ）
A:promoter B:enhancer C:insulator D:operator 11. Enhancers must locate on the upstream region of promoter.（ ）
A:对 B:错 12.The active chromatin usually shows low level of methylation.（ ）
A:错 B:对