核糖体含有的与tRNA有关的3个功能部位是( )部位、( )部位和( )部位。

每个ORF一般以( )开始，以( )结束。原核生物的mRNA通常是( )顺反子，而真核生物的mRNA为( )顺反子。

翻译时阅读mRNA的方向都是( )，多肽链的延伸方向是( )，正确的氨基酸渗入取决于( )间的相互作用。

All the following statements about genetic code are correct except:

A. It is degenerate
B. It is unambiguous
C. It is nearly universal
D. It is overlapping

A codon AUG is a:

A. Chain-initiating codon
B. Chain-terminating codon
C. Releasing factor for peptide chains
D. Recognition site on the tRNA

In biosynthesis of proteins, the chain-terminating codons are:

A. UAA, UAC and UGA
B. UGG, UGU and AGU
C. AAU, AAG and GAU
D. GCG, GCA and GCU

Formation of initiation complex in protein biosynthesis involves:

A. Dissociation of ribosome into its 40S and 60S subunits
B. Formation of 48S initiation complex
C. Formation of 80S initiation complex
D. All of the above

In contrast to eukaryotic mRNA, prokaryotic mRNA:

A. has a poly A tail
B. has 7-methylguanosine at the 5′ end
C. can be polycistronic
D. none of the above