37. The hydrogen bonding interactions in a Watson-Crick AT base-pair involve what units in the adenine base?
(A) N-1 and the amino group on C-6
(B) N-1 and N-3
(C) N-7 and the amino group on C-6
(D) N-7 and C-8

33. A 10-year-old girl is brought by her parents to the dermatologist. She has many freckles on her face, neck, arms, and hands, and the parents report that she is unusually sensitive to sunlight. Two basal cell carcinomas are identified on her face. Based on the clinical picture, which of the following processes is most likely to be defective in this patient? (A) Removal of pyrimidine dimers from DNA by nucleotide excision repair (B) Removal of mismatched bases from the 3'-end of Okazaki fragments by a methyl-directed process (C) Repair of double-strand breaks by error-prone homologous recombination (D) Removal of uracil from DNA by base excision repair

34. During RNA synthesis, the DNA template sequence TAGC would be transcribed to produce which of the following sequences? (A) ATCG (B) CGTA (C) AUCG (D) GCUA

35. Methylation and subsequent deamination of cytosine produces what type of mutation after one round of DNA replication? (A) C-to-T transversion (B) C-to-T transition (C) G-to-A transition (D) C-to-A transversion HSING UNI

36. As a measure of quality control in translation, which component of the translation machinery is capable of proofreading and editing amino acids? (A) the ribosome (B) Aminoacyl-tR.NA synthetases (C) tRNAs (D) RNA polymerase

38. Splice sites in pre-mRNA are marked by two universally conserved sequences contained (A) in the middle of the intron. (B) at the ends of the exons. (C) at the ends of the introns. (D) None of the above

39. An isolate of a mutant bacterium appears to grow more slowly than the wild-type popuiation from (which it was isolated. Further studies showed that the slower growth was due to a markedly reduced DNA polymerase I activity. From this information, one would expect that this organism would also be deficient in the activity of DNA (A) excision repair. (B) recombination. (C) transcription. (D) translation.

40. Which of the following molecules can be considered a final product in the flow of genetic information within a cell? (A) DNA (B) RNA (C) Protein (D) Protein or RNA can be the final product of a gene.

41. Which of the following is not a reason for the importance of mRNA processing in eukaryotes? (A) Longevity in the cytoplasm (B) Coupling of transcription and translation (C) Turnover in the cytoplasm (D) Removal of introns

42. Of the following steps associated with translation, which does not involve hydrolysis of GTP? (A) Aminoacylation oftRNA (B) Formation of the initiation complex (C) Binding of the aminoacyl tRNA to the codon at the A site (D) Translocation of the ribosome

43. In eukaryotes, the 3' end of the mRNA is important in the initiation of translation because (A) it contains Kozak sequences that aid in initiation. (B) translation occurs in the 3' to 5' direction. (C) elF4A is attached to the 3' cnd and removes any sccondary structure that might prevent translation. (D) the 3' poly( A ) tail and PABP bind initiation factor elF4G, stabilizing the 5' end of the mRNA.