5. What is CPSF? & its unctions? (5%)

4. Why is the lactose operon not induced in the presence of both lactose and glucose? (2%)

3. Eukaryotes have three RNA polymerases. What are they and what does each do? (3 %)

40. A characteristic of RNA polymerase in humans that is different from bacterial RNA polymerase is
(A) that in humans, there are three distinct nuclear RNA polymerases and only one in bacteria.
(B) that in bacterial RNA polymerase is directly recruited to the promoter but in human RNA polymerase is recruited to a
pre-initiation complex.
(C) that in human RNA polymerase many additional transcription factors must bind the promoter first before RNA polymerase is
recruited; whereas in bacteria only the sigma factor is required.
(D) All the above are characteristics of RNA polymerase that differ between human and bacteria.

II. Essay questions (20%): Please answer the following question as sufficient as you can.

39. TFIID is one of the basal transcription factors to bind the promoter during the assembly of the pre-initiation complex, which of
the following statements about TFIID is FALSE?
(A) TFIID distorts the DNA duplex when it binds.
(B) TFIID binds the TATA box in promoters.
(C) TFIID binds the DNA only after basal transcription factors have bond the promoter region.
(D) TFIID binds Inr and DPE elements in promoters.

38. In the lac operon, which region of the operon does the repressor bind?
(A) Promoter
(B) Operator
(C) CAMP-CRF binding site
(D) +1 start of transcription