32. A three-base sequence (loop) in tRNA that is complementary to a sequence of three bases in mRNA is a(n)__?
(A) amino acid attachment site；
(B) promoter；
(C) codon；
(D) anticodon.

28. The net ATP production in glycolysis is only two because__? (A) two ATPs are used to "activate" glucose, while 4 ATPs are produced in remaining glycolysis steps；(B) two ATPs are used to donate electrons, in order to move NADH into the mitochondria；(C) None of the answer choices are correct, because six ATPs are the net yield from glycolysis；(D) that is the needed number of ATPs to power the reactions of the Krebs cycle.

29. The "Central Dogma" refers to__? (A) passage of genetic information from RNA to specific proteins by transcription；(B) inheritance of DNA genetically controlled traits from parents to offspring in every organism；(C) the similarity of the energy molecule ATP to the nucleotides in DNA；(D) the flow of genetic information in cells, from DNA genes to specific proteins.

30. The statement that does not correctly associate an RNA type, and its function, is__? (A) complementary RNA reorders the amino acids to insure their correct sequence；(B) messenger RNA is the gene, carrying coding to control the building of proteins；(C) transfer RNA functions to carry amino acids to the ribosome；(D) ribosomal RNA functions as a catalyst to bind amino acids into proteins.

31. A DNA sequence that signals a gene's start is a(n)__? (A) amino acid attachment site；(B) promoter；(C) codon；(D) anticodon.

33. In the Lac operon, the protein that binds to the operator to prevent transcription is__? (A) the promoter；(B) RNA polymerase；(C) the repressor；(D) DNA polymerase.

34. Which proteins initiate transcription in eukaryotes by recognizing sequences within the promoter region of a gene and attracting RNA polymerase? (A) TATA boxes；(B) transcription factors；(C) inducers；(D) repressors.

35. In a "silent" mutation the__? (A) codon that mutates causes a change in the amino acid specified；(B) codon that mutates does not cause a change in the amino acid specified；(C) mutation does not occur in a codon；(D) codon that mutates causes a stop codon to occur instead of the placement of an amino acid.

36. Transposable elements__? (A) result from damage to the chromosomes by things like radiation；(B) are DNA sequences that can "jump" within the genome；(C) are another name for translocations；(D) are segments of RNA found in chromosomes.

37. Using the genetic code shown here, predict what type of mutation has occurred in the hemoglobin sickle cell anemia allele. Normal allele 5'–GGAAUGAAACAGGAACCC–3'Mutant allele 5'–GGAAUGAAACAGGUACCC–3'(A) a point mutation, Glu to Val (B) a point mutation, Val to Glu (C) a frameshift mutation (D) addition of a new stop codon

38. What type of mutation has occurred in the following?Normal allele 5'–GGAAUGAAACAGGAACCC–3'Mutant allele 5'–GGAAUGAAACAGGUACCC–3' (A) deletion of one base；(B) substitution；(C) deletion of two bases；(D) insertion of two bases.