資訊推薦

• 29. Which enzyme catalyzes the elongation of a DNA strand in the 5' → 3' direction?(A) pri
• 30. Which component is not directly involved in translation?(A) mRNA(B) DNA(C) tRNA(D) ribosomes
• 31. Which of the following is not true of RNA processing?(A) Exons are cut out before mRNA leaves th
• 32. Sickle-cell disease is probably the result of which kind of mutation?(A) point(B) frameshift(C)
• 33. What are polyribosomes?(A) groups of ribosomes reading a single mRNA simultaneously(B) ribosomes
• 34. The role of a metabolite that controls a repressible operon is to(A) bind to the promoter region
• 35. Genomic imprinting, DNA methylation, and histone acetylation are all examples of(A) genetic muta
• 36. In both eukaryotes and prokaryotes, gene expression is primarily regulated at the level of(A) tr
• 37. The host range of a virus is determined by(A) the proteins on its surface and that of the host(B
• 38. What is the function of reverse transcriptase in retroviruses?(A) It hydrolyzes the host cell�
• 39. What are prions?(A) misfolded versions of normal brain protein(B) tiny molecules of RNA that inf
• 40. What is the name given to viruses that are single-stranded RNA that acts as a template for DNA s
• 41. What is the enzymatic function of restriction enzymes?(A) to add new nucleotides to the growing
• 42. Bacteria containing recombinant plasmids are often identified by which process?(A) examining the
• 43. A gene that contains introns can be made shorter (but remain functional) for genetic engineering
• 44. The first cell whose entire genome was sequenced was which of the following?(A) H. influenzae in
• 45. Which of the following is a representation of gene density?(A) Humans have 2,900 Mb per genome(B
• 46. Why might the cricket genome have 11 times as many base pairs than that of Drosophila melanogast
• 47. Several of the different globin genes are expressed in humans, but at different times in develop
• 48. In Darwin's thinking, the more closely related two different organisms are, the(A) more sim
• 49. Of the following anatomical structures, which is homologous to the wing of a bird?(A) Dorsal fin
• 50. Each of the following has a better chance of influencing gene frequencies in small populations t
• 51. Which free-living cells were the earliest contributors to the formation of Earth's oxidizin
• 52. The scientific discipline concerned with naming organisms is called(A) taxonomy(B) cladistics(C)
• 53. Which of the following are responsible for high levels of O2 in Earth's atmosphere?(A) phot