原核细胞RNA聚合酶只有( )种，全酶由核心酶和可变的( )因子组装而成。

真核细胞RNA聚合酶：( )合成18S、5.8S和28SRNA；( )合成mRNA前体和snRNA；( )合成tRNA和5SRNA。

原核转录系统识别启动子的是( )，真核转录系统识别启动子的是特定的( )。

原核细胞启动子的共有序列有-35区的( )和-10区的( )。

真核细胞核mRNA的加帽、加尾和剪接都是共转录反应。

A. 对
B. 错

Which of the following is true for the process of RNA synthesis?

A. Occurs in the 3′ to 5′ direction
B. Requires primer
C. Does not require primer
D. Is initiated at special DNA sequences known as start condons

Eukaryotic promoters contain:

A. TATA box 25 bp upstream of transcription start site
B. CAAT box 70 to 80 bp upstream of transcription start site
C. Both (a) and (b)
D. None of these

A consensus sequence on DNA, called TATA box, is the site for attachment of:

A. RNA-dependent DNA polymerase
B. DNA-dependent RNA polymerase
C. DNA-dependent DNA polymerase
DNA topoisomerase II

Sigma and Rho factors are required for:

A. Replication
B. Transcription
C. Translation
D. Polymerization

Noncoding sequences in a gene are known as:

A. Cistron
B. Nonsense codons
C. Introns
D. Exons