Question 1 Base pairing A. requires hydrogen bonds. B. occurs between identical bases. C. takes place between sugars and phosphates on the two strands in a helix. D. explains the X-ray results from Rosalind Franklin. E. occurs between A and C. . 5 points Question 2 DNA replication A. does not require proteins. B. takes place in the nucleus of the cell. C. occurs in G1 of interphase. D. occurs in the cytoplasm of the cell. E. is constantly happening in a cell. . 5 points Question 3 The fact that the two strands composing a DNA molecule are called antiparallel has to do with the orientation of the A. sugar molecules. B. bases. C. hydrogen bonds. D. sulfide bonds. E. phosphate molecules. . 5 points Question 4 The most important experimental results that suggested to Watson and Crick that DNA was in the form of a helix was A. the findings of Chargaff that DNA always had equal amounts of A and T and equal amounts of G and C. B. understanding DNA replication. C. X-ray data from Rosalind Franklin. D. the discovery that DNA is wound around histone proteins. E. Griffithâ€™s results with transformation. . 5 points Question 5 What step in DNA replication precedes the pairing of complementary bases? A. mitotic division. B. polymerization of DNA. C. separation of the two strands. D. joining of the two strands. E. formation of the histone core. . 5 points Question 6 A component of bacteria that are often used in biotechnology are A. exons. B. operons. C. introns. D. plasmids. E. polypeptides. . 5 points Question 7 Normal human body cells contain how many chromosomes? A. 42 B. 46 C. 23 D. 22 E. 44 . 5 points Question 8 In recombinant DNA technology, enzymes used to precisely cut DNA are called A. RNA polymerases. B. DNA polymerases. C. vectors. D. DNA ligases. E. restriction enzymes. . 5 points Question 9 What form of RNA carries instructions from the nucleus to the ribosome? A. sRNA B. rRNA C. tRNA D. mRNA E. bRNA . 5 points Question 10 The two subunits of the ribosome join during A. termination of transcription. B. termination of translation. C. initiation of translation. D. elongation. E. promotion of transcription. . 5 points Question 11 In eukaryotes, transcription occurs in the A. cytoplasm. B. nucleus. C. ribosome. D. mitochondria. E. cell membrane. . 5 points Question 12 In DNA, cytosine bonds to guanine. In RNA, cytosine bonds to A. uracil. B. guanine. C. thymine. D. cytosine. E. adenine. . 5 points Question 13 The bases are bonded to what part of the backbone of the DNA molecule? A. the 4â€™ carbon atom of the sugar molecule. B. the 5â€™ carbon atom of the sugar molecule. C. the 2â€™ carbon atom of the sugar molecule. D. the 1â€™ carbon atom of the sugar molecule. E. the 3â€™ carbon atom of the sugar molecule. . 5 points Question 14 The anticodon of the tRNA molecule base pairs with A. polypeptides. B. amino acids. C. mRNA. D. rRNA. E. DNA. . 5 points Question 15 DNA replication of a single DNA molecule is referred to as semiconservative because A. one DNA strand is replicated continuously, while the other must be replicated discontinuously. B. of the two DNA molecules, one is made up totally of parental DNA, while the other is entirely newly synthesized DNA. C. each of the two DNA molecules will consist of one parental strand and one newly synthesized strand. D. it results in two nonidentical DNA molecules. E. all the DNA strands in the two DNA molecules will have both parental and newly synthesized DNA. . 5 points Question 16 A package of histones with DNA wrapped around them forms spherical structures called A. lysosomes. B. nucleoli. C. nucleosomes. D. chromatin. E. ribosomes. . 5 points Question 17 What enzyme is used to â€œglueâ€ together the ends of cut pieces of DNA? A. protease B. restriction enzymes C. DNA ligase D. DNA polymerase E. RNA polymerase . 5 points Question 18 Hershey and Chase performed an experiment in which they used radioactive isotopes to phosphorus and sulfur to label different components of bacterial viruses. Their results clearly showed that A. genetic material normally contains radioactive isotopes. B. DNA was entering into the infected bacteria. C. the viruses did not contain DNA. D. protein was entering into the infected bacteria. E. the viruses did not contain protein. . 5 points Question 19 We refer to the DNA code as being redundant or repetitive. This means that A. one codon codes for one amino acid. B. a single triplet may code for more than one amino acid. C. each triplet codes for one amino acid. D. each triplet codes for a different amino acid. E. some codons code for the same amino acid. . 5 points Question 20 When looking at a table depicting the genetic code, the base sequences signify A. tRNA. B. rRNA. C. mtDNA. D. mRNA. E. DNA.