MCQOPTIONS
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MCQOPTIONS
This section includes 92 Mcqs, each offering curated multiple-choice questions to sharpen your Cell Biology knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
How wide is chromatid? |
| A. | 100 nm |
| B. | 200 nm |
| C. | 1000 nm |
| D. | 700 nm |
| Answer» E. | |
| 52. |
Which of following enzymes swivels and rejoins DNA to release tension created by replication? |
| A. | telomerase |
| B. | topoisomerase |
| C. | helicase |
| D. | proteases |
| Answer» C. helicase | |
| 53. |
What is initial error rate of DNA replication? |
| A. | 10⁵ |
| B. | 10² |
| C. | 10⁹ |
| D. | 10¹ |
| Answer» B. 10² | |
| 54. |
How many DNA repair enzymes have been found so far in humans? |
| A. | 2 |
| B. | 100 |
| C. | 150 |
| D. | 900 |
| Answer» C. 150 | |
| 55. |
Bases are stacked apart at how much distance? |
| A. | 0.34 |
| B. | 0.1 |
| C. | 0.25 |
| D. | 0.65 |
| Answer» B. 0.1 | |
| 56. |
Which of following proteins are responsible for first level packaging of DNA? |
| A. | hemoglobin |
| B. | chromatin |
| C. | histones |
| D. | helicase |
| Answer» D. helicase | |
| 57. |
Changes in telomere with time are associated with which of following? |
| A. | apoptosis |
| B. | cancer |
| C. | aging |
| D. | respiration |
| Answer» D. respiration | |
| 58. |
What is error rate in final DNA replicated molecule? |
| A. | 1 in 10,000 |
| B. | 1 in 500 |
| C. | 1 in 10 |
| D. | 1 in 10¹⁰ |
| Answer» E. | |
| 59. |
Which of following is a DNA cutting enzyme? |
| A. | topoisomerase |
| B. | helicase |
| C. | protease |
| D. | nuclease |
| Answer» B. helicase | |
| 60. |
How many nucleotide pairs are present in E Coli? |
| A. | 4.6 million |
| B. | 8 million |
| C. | 100000 |
| D. | 500 million |
| Answer» B. 8 million | |
| 61. |
A defect in DNA repair enzymes is one of causative factors of |
| A. | alzheimer's disease |
| B. | parkinson's disease |
| C. | cancer |
| D. | polio |
| Answer» D. polio | |
| 62. |
Which of following play a part in DNA synthesis? |
| A. | polymerase I |
| B. | polymerase II |
| C. | polymerase IV |
| D. | polymerase V |
| Answer» B. polymerase II | |
| 63. |
Which of following structures of DNA was erroneously proposed by Linus Pauling? |
| A. | triple stranded |
| B. | double stranded |
| C. | aplha |
| D. | alpha helix |
| Answer» B. double stranded | |
| 64. |
Loose packaging of which of following makes DNA more accessible to transcription machinery? |
| A. | clumped chromatin |
| B. | diffused chromatin |
| C. | Euchromatin |
| D. | heterochromatin |
| Answer» D. heterochromatin | |
| 65. |
In which of following cells activity of telomerase is abnormally high? |
| A. | heart cells |
| B. | cancer cells |
| C. | muscle cells |
| D. | none of above |
| Answer» C. muscle cells | |
| 66. |
What is diameter of DNA double helix in a eukaryotic cell? |
| A. | 1 nm |
| B. | 3 nm |
| C. | 5 nm |
| D. | 2 nm |
| Answer» E. | |
| 67. |
About how many enzymes participate in DNA replication? |
| A. | 12 |
| B. | 90 |
| C. | 100 |
| D. | 2 |
| Answer» B. 90 | |
| 68. |
Telomeres undergo which of following changes in each replication round? |
| A. | shorten |
| B. | elongate |
| C. | no change |
| D. | fall off |
| Answer» B. elongate | |
| 69. |
Which of following enzymes joins sugar-phosphate backbone? |
| A. | helicase |
| B. | topoisomerase |
| C. | ligase |
| D. | proteases |
| Answer» D. proteases | |
| 70. |
Spontaneous and permanent changes in DNA sequence are called |
| A. | mutations |
| B. | changes |
| C. | deletions |
| D. | translocations |
| Answer» B. changes | |
| 71. |
Which of following molecules make backbone of DNA molecule? |
| A. | sugar-phosphate |
| B. | sugar-base |
| C. | base-phosphate |
| D. | base-sugar-phosphate |
| Answer» B. sugar-base | |
| 72. |
Which of following binds to and stabilizes single-stranded DNA until it is used as a template? |
| A. | helicase |
| B. | topoisomerase |
| C. | DNA polymerase I |
| D. | single strand binding proteins |
| Answer» E. | |
| 73. |
Which of following techniques is used by Crick to study protein structure? |
| A. | electron microscope |
| B. | microscope |
| C. | X ray crystallography |
| D. | circular dichroism |
| Answer» D. circular dichroism | |
| 74. |
Which of following compensates for telomere shortening? |
| A. | topoisomerase |
| B. | telomere repair |
| C. | helicase |
| D. | telomerase |
| Answer» E. | |
| 75. |
Xeroderma pigmentosum is caused by a defect in which of following enzymes? |
| A. | helicase |
| B. | topoisomerase |
| C. | protease |
| D. | nucleotide excision repair enzyme |
| Answer» E. | |
| 76. |
Which of following is not a nitrogenous base of DNA? |
| A. | alanine |
| B. | guanine |
| C. | adenine |
| D. | cytosine |
| Answer» B. guanine | |
| 77. |
Interphase chromatin visible as irregular clumps is called |
| A. | clumped chromatin |
| B. | diffused chromatin |
| C. | Euchromatin |
| D. | heterochromatin |
| Answer» E. | |
| 78. |
Which of following enzymes catalyzes synthesis of new DNA strand? |
| A. | primase |
| B. | topoisomerase |
| C. | helicase |
| D. | DNA polymerase |
| Answer» E. | |
| 79. |
Which of following extends out at end of nucleosome? |
| A. | histone tail |
| B. | DNA 3 prime end |
| C. | DNA 5 prime end |
| D. | linker DNA |
| Answer» B. DNA 3 prime end | |
| 80. |
How many nucleotides long is Okazaki fragment in eukaryotes? |
| A. | 100 |
| B. | 10 |
| C. | 20 |
| D. | 1000 |
| Answer» B. 10 | |
| 81. |
Which of following is an example of a purine base? |
| A. | thymine |
| B. | uracil |
| C. | adenine |
| D. | cytosine |
| Answer» D. cytosine | |
| 82. |
DNA helix makes one full turn after what distance along its length? |
| A. | 10 nm |
| B. | 5 nm |
| C. | 3.4 nm |
| D. | 1 nm |
| Answer» D. 1 nm | |
| 83. |
An RNA primer is consist of how many nucleotides? |
| A. | 3 |
| B. | 30 |
| C. | 20 |
| D. | 10 |
| Answer» E. | |
| 84. |
Complex of DNA and proteins is called |
| A. | chromosome |
| B. | linker DNA |
| C. | chromatin |
| D. | nucleolus |
| Answer» D. nucleolus | |
| 85. |
Which of following bases is exclusive to RNA molecules? |
| A. | guanine |
| B. | thymine |
| C. | cytosine |
| D. | uracil |
| Answer» E. | |
| 86. |
Which of following bases binds with Uracil in RNA? |
| A. | guanine |
| B. | cytosine |
| C. | adenine |
| D. | thymine |
| Answer» D. thymine | |
| 87. |
How many different DNA polymerases have been found in eukaryotes? |
| A. | 1 |
| B. | 2 |
| C. | 45 |
| D. | 11 |
| Answer» E. | |
| 88. |
What is rate of elongation of DNA in humans? |
| A. | 1 per second |
| B. | 10 per second |
| C. | 50 per second |
| D. | 100 per second |
| Answer» D. 100 per second | |
| 89. |
Y shaped region where parent DNA strands are being unwound is called |
| A. | replication fork |
| B. | replication bubble |
| C. | Y fork |
| D. | helix |
| Answer» B. replication bubble | |
| 90. |
How many genes are present in E Coli? |
| A. | 4400 |
| B. | 1000 |
| C. | 100 |
| D. | 6000 |
| Answer» B. 1000 | |
| 91. |
Replication of DNA molecule follows which of following rule? |
| A. | conservative |
| B. | semi conservative |
| C. | replicative |
| D. | destructive |
| Answer» C. replicative | |
| 92. |
Nucleosomes have which of following function besides DNA packaging? |
| A. | gene silencing |
| B. | gene expression |
| C. | DNA replication |
| D. | protein translation |
| Answer» C. DNA replication | |