51. In the semi-conservative model each daughter DNA consists of:
Answer: C. one parental and one new strand
Biology Class 11 Unit 13: Chromosome and DNA MCQs
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52. In the conservative model one daughter DNA has:
Answer: B. both parental strands, and the other has both new strands
53. In the dispersive model the parental DNA:
Answer: B. is dispersed into fragments which combine with new nucleotides
54. Meselson and Stahl did their experiment in:
Answer: C. 1958
55. Meselson and Stahl used the heavy isotope of:
Answer: C. nitrogen (15N)
56. They separated the DNA by:
Answer: C. cesium chloride density gradient ultracentrifugation
57. After one generation in 14N medium the DNA appeared:
Answer: C. intermediate (hybrid)
58. After two generations the DNA showed:
Answer: D. two bands, one light and one intermediate
59. Meselson and Stahl proved that DNA replication is:
Answer: C. semi-conservative
60. The point where replication begins is the:
Answer: C. origin of replication
61. In prokaryotes the number of origins of replication is:
Answer: C. one
62. Eukaryotic DNA has:
Answer: B. more than one origin of replication
63. The enzyme that opens the DNA duplex by breaking base pairs is:
Answer: C. DNA helicase
64. The enzyme that reduces the tension created during unwinding is:
Answer: B. DNA gyrase
65. The proteins that prevent single strands from re-pairing are:
Answer: B. single-strand binding (SSB) proteins
66. The Y-shaped region on each side of the replication bubble is the:
Answer: B. replication fork
67. The enzyme which synthesizes RNA primers is:
Answer: D. primase
68. The complex of primase and helicase is called the:
Answer: C. primosome
69. The enzyme which synthesizes the daughter strand is:
Answer: B. DNA polymerase
70. DNA polymerase adds nucleotides to the:
Answer: B. 3 prime end of the primer
71. Synthesis of DNA is in the direction:
Answer: B. 5 prime to 3 prime
72. DNA polymerase III:
Answer: C. is the main enzyme of replication
73. DNA polymerase II is involved in:
Answer: B. repair of DNA damages
74. DNA polymerase I:
Answer: B. removes RNA primers and fills the gaps with DNA nucleotides
75. The continuously synthesized daughter strand is the:
Answer: B. leading strand
76. The discontinuously synthesized daughter strand is the:
Answer: B. lagging strand
77. The short fragments of the lagging strand are called:
Answer: B. Okazaki fragments
78. The enzyme that joins Okazaki fragments is:
Answer: C. DNA ligase
79. The ability of DNA polymerase to remove a wrongly added nucleotide is called:
Answer: B. proofreading
80. Which enzyme could be missing if replication gives DNA with many short fragments joined to the normal strand?
Answer: B. DNA ligase
81. Errors in DNA replication result in:
Answer: B. mutations and genetic variation
82. The idea that DNA makes protein via RNA is the:
Answer: B. central dogma
83. Gene expression includes:
Answer: B. transcription and translation
84. Transcription is the synthesis of:
Answer: C. RNA from a DNA template
85. Transcription requires only one enzyme which is:
Answer: B. RNA polymerase
86. The three phases of transcription are:
Answer: B. initiation, elongation and termination
87. The region of a gene where RNA polymerase binds is the:
Answer: C. promoter
88. The prokaryotic promoter sequences are:
Answer: B. TATAAT (minus 10) and TTGACA (minus 35)
89. Eukaryotic promoter contains:
Answer: B. TATA box, CAAT box and GC-rich box
90. The TATA box is located at about:
Answer: C. minus 25
91. The CAAT box is located at about:
Answer: B. minus 80
92. Prokaryotic RNA polymerase core enzyme has how many subunits?
Answer: C. Four subunits (two alpha and two beta types)
93. The factor needed for RNA polymerase to bind the promoter is the:
Answer: B. sigma factor
94. The core enzyme plus sigma factor is called the:
Answer: B. holoenzyme
95. Eukaryotic RNA polymerase I synthesizes:
Answer: C. rRNA
96. Eukaryotic RNA polymerase II synthesizes:
Answer: C. mRNA
97. RNA polymerase III synthesizes:
Answer: C. tRNA
98. RNA polymerase does not require a:
Answer: C. primer
99. The strand of the gene which is used as a template is also called:
Answer: C. antisense strand
100. The strand having the same sequence as mRNA is the:
Answer: C. coding (sense) strand
About Biology Class 11 Unit 13 MCQs (Federal Board)
These 228 Biology MCQs cover Class 11 Unit 13: Chromosome and DNA of the Federal Board (FBISE) HSSC-I (1st Year / Class 11) syllabus. They are SLO-based MCQs as per the new pattern for FBISE exams. Each question has four options and the correct answer is shown, so you can practise for the annual examination and find the topics you still need to revise. The questions are split over 5 pages of 50. Use the Print button to save this chapter as a PDF.