24. An enhancer
(A)is a protein that binds to RNA polymerase and stimulates transcription.
(B) interacts with repressor proteins to enhance transcriptional repression.
(C) binds to RNA polymerase and stimulates transcription.
(D) is a DNA element that increases transcription.

20. All of the following can be found in chromatin except (A) DNA. (B) histones. (C) RNA. (D) transcription factors.

21. Telomeres (A) consist of repetitive sequences with high G content. (B) are a few hundred base-pairs long in vertebrates. (C) have specific proteins bound at the DNA ends. (D) A and C (E) All of the above

22. Which of the following sequential order for the secretory pathway is false? (A)Rough endoplasmic reticulum (ER) → ER-to-Golgi transport vesicles → Golgi cisternae →  secretory vesicles. (B) Rough ER → ER-to-Golgi transport vesicles → Golgi cisternae → Mitochondria. (C) Plasma membrane →  Early endosome → Late endosome → Lysosome. (D)Rough ER → ER-to-Golgi transport vesicles → Golgi cisterae →  Late endosome →  Lysosome.

23. Most eukaryotic genes are controlled at the level of (A) transcription initiation. (B) transcription elongation. (C) transcription termination. (D) translation initiation.

25. Which of the following sequences functions as a promoter for transctiption? (A) TATA box. (B) initiator. (C) CpG islands. (D) all of the above (E) none of the above

26. Which of the following statements regarding RNA splicing is correct? (A) initiation of transcription, splicing, addition of 5"' cap, addition of poly-A tail, transport to cytoplasm (B) initiation of transcription, addition of 5' cap, splicing, addition of poly-A tail, transport to cytoplasm (C) initiation of transcription, addition of poly-A tail, addition of 5' cap, splicing, transport to cytoplasm (D) initiation of transcription, addition of 5' cap, addition of poly-A tail, splicing, transport to cytoplasm

27. Which of following events does not occur within the nucleus? (A) protein phosphorylation (B) RNA capping (C) polyadenylation (D) splicing

28. Which of the following is not used in the electrophoretic mobility shift assay (EMSA)? (A) a radiolabeled DNA fragment (B) a polyacrylamide gel (C) a DNA binding protein (D) DNase I

29. RNA editing is (A) post-transcriptional alteration of sequences in mRNAs. (B) pre-transcriptional alteration of sequences in RNAs. (C) post-transcriptional joining of two RNA molecules. (D) none of the above

30. Which of the following is most likely to lead to a loss of gene function? (A) A sequence change in the 3' untranslated region. (B) A change from a TAA codon to a TAG codon in the coding region. (C) A change from T to C in the promoter region. (D) A frameshift mutation in the coding region.