691. The complex of RNA polymerase, DNA template and new RNA transcript is called
A. transcription bubble
B. replication bubble
C. a translation bubble
D. none of these

692. RNA polymerase in prokaryotes has a removable
A. alpha subunit
B. beta subunit
C. both (a) and (b)
D. sigma subunit

693. Promoters for tRNAs are located
A. upstream from the start codon
B. downstream from the start codon
C. both (a) and (b)
D. none of these

694. The binding of lac repressor to DNA could be considered to be analogous to
A. competitive inhibition of an enzyme
B. mixed-type inhibition of an enzyme
C. uncompetitive inhibition of an enzyme
D. allosteric effects in enzyme regulation

695. Rho-dependent termination of transcription in E. coli
A. requires ATP
B. requires about 50 nucleotides of uncomplexed mRNA
C. both (a) and (b)
D. removes mRNA and holoenzyme from the DNA

696. Enhancers are regions that
A. bind RNA polymerase
B. are adjacent to the TATA box
C. are CAT box binding proteins
D. modulate transcription

697. Transcription by E. coli polymerase occurs in
A. four phases known as initiation, propagation, elongation and termination
B. three phases known as initiation, elongation and termination
C. two phases known as initiation and termination
D. none of the above

698. Which of the following is necessary for transcription to occur?
A. DNA molecule
B. RNA polymerase
C. DNA polymerase
D. Both DNA & RNA polymerase

699. Multiple copies of 5S genes, located at a chromosomal site distinct from the other rRNA genes
A. are transcribed by rRNA polymerase III and the 5S rRNA
B. are transcribed by rRNA polymerase II
C. are transcribed by rRNA polymerase I and the 5S rRNA
D. are transcribed by DNA polymerase I

700. Each tRNA molecule has a cloverleaf secondary structure consisting of
A. three stem loops
B. two stem loops
C. four stem loops
D. either (a) or (b)