MCQOPTIONS
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MCQOPTIONS
This section includes 205 Mcqs, each offering curated multiple-choice questions to sharpen your Life Sciences knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
The tRNA carries amino acids to the ____________ |
| A. | rRNA |
| B. | mRNA |
| C. | sRNA |
| D. | hnRNA |
| Answer» C. sRNA | |
| 52. |
Fatty acids are oxidized to acetyl-CoA by which of the following pathways? |
| A. | β-oxidation |
| B. | Entner-Doudoroff |
| C. | pentose phosphate pathway |
| D. | Embden-Meyerhof pathway |
| Answer» B. Entner-Doudoroff | |
| 53. |
A reducing agent will accept electrons and an oxidizing agent will donate electrons. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 54. |
The enzymes that catalyze the reactions of the Krebs cycle are found in which subcellular organelle of eukaryotes? |
| A. | Mitochondrion |
| B. | Chloroplast |
| C. | Ribosome |
| D. | Endoplasmic reticulum |
| Answer» B. Chloroplast | |
| 55. |
Dolichol phosphate is |
| A. | a complex lipid involved in docking vesicles with the plasma membrane |
| B. | the anchor on which sugars assemble before transfer to proteins |
| C. | a chaperone used in protein folding |
| D. | a product of phospholipase C activation |
| Answer» C. a chaperone used in protein folding | |
| 56. |
Which of the following catalyze liberation of orthophosphate from organic P compounds and inorganic pyrophosphate ? |
| A. | Alkaline phosphates |
| B. | Oxidoreductase |
| C. | Protease |
| D. | Hydrogenase |
| Answer» B. Oxidoreductase | |
| 57. |
tRNA has a _______________ structure. |
| A. | strand-like |
| B. | ball-like |
| C. | clover-leaf |
| D. | leaf-like |
| Answer» D. leaf-like | |
| 58. |
Basal metabolism refers to the amount of energy required to |
| A. | eat dinner |
| B. | carry out all the vital processes |
| C. | run a marathon |
| D. | keep heart beating |
| Answer» C. run a marathon | |
| 59. |
Which of the following are features of semiconservative replication? |
| A. | RNA replicates DNA molecule |
| B. | The DNA molecule produced contains two old templates |
| C. | One new DNA helix is formed |
| D. | DNA duplicates itself and the new chain contains old template strand and new complementary strand |
| Answer» E. | |
| 60. |
RNA consists of which combination of bases? |
| A. | Thymine,Guanine,Cytosine |
| B. | Guanine,Cytosine,Uracil |
| C. | Thymine,Adenine,Guanine |
| D. | Adenine,Cytosine,Thymine |
| Answer» C. Thymine,Adenine,Guanine | |
| 61. |
The phosphate inhibition in the clavine formation with Claviceps SD58, can be counteracted by the addition of |
| A. | alanine |
| B. | methionine |
| C. | tryptophan |
| D. | lysine |
| Answer» D. lysine | |
| 62. |
The final electron acceptor in the electron transport chain is |
| A. | CoQ |
| B. | a cytochrome |
| C. | FMN |
| D. | oxygen |
| Answer» E. | |
| 63. |
Which of the following are non-sense codons? |
| A. | AUG |
| B. | GUG |
| C. | UAA |
| D. | UCU |
| Answer» D. UCU | |
| 64. |
ATPase |
| A. | synthesizes ATP, coupled to transfer of extracellular protons into the cell |
| B. | extrudes protons from the cell coupled to the hydrolysis of ATP to ADP |
| C. | is the enzyme that incorporates ATP into messenger RNA |
| D. | carries out each of the reactions indicated in (a) and (b) |
| Answer» E. | |
| 65. |
Most of the energy in aerobic respiration of glucose is captured by |
| A. | substrate-level phosphorylation |
| B. | electron transport of electrons from NADH |
| C. | long-chain fatty acid oxidation |
| D. | the enzyme formic-hydrogen lyase |
| Answer» C. long-chain fatty acid oxidation | |
| 66. |
Glucose can be broken down to pyruvate by |
| A. | Entner-Doudoroff pathway |
| B. | tricarboxylic acid cycle |
| C. | both (a) and (b) |
| D. | none of these |
| Answer» B. tricarboxylic acid cycle | |
| 67. |
As the electron flow through the chains, much of their free energy is conserved in the form of ATP. This process is called |
| A. | oxidative phosphorylation |
| B. | electromotive potential |
| C. | dehydrogenations |
| D. | none of these |
| Answer» B. electromotive potential | |
| 68. |
Before most molecules can enter the Krebs citric acid cycle, they must be converted to |
| A. | citric acid |
| B. | oxaloacetic acid |
| C. | NADH or FADH |
| D. | acetyl-CoA |
| Answer» E. | |
| 69. |
Translation takes place before transcription. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 70. |
Nitrogen fixation is a process that requires |
| A. | energy |
| B. | an anaerobic environment |
| C. | both (a) and (b) |
| D. | an aerobic environment |
| Answer» D. an aerobic environment | |
| 71. |
The reactions of the cell that are carried out for capturing energy are called |
| A. | catabolism |
| B. | metabolism |
| C. | anabolism |
| D. | activation energy |
| Answer» B. metabolism | |
| 72. |
In the passive diffusion, solute molecules cross the membrane as a result of |
| A. | concentration difference |
| B. | pressure difference |
| C. | ionic difference |
| D. | all of these |
| Answer» B. pressure difference | |
| 73. |
Anoxygenic photosynthetic bacteria oxidize |
| A. | water |
| B. | oxgyen |
| C. | sulfide |
| D. | ammonia |
| Answer» D. ammonia | |
| 74. |
The major route for incorporation of ammonia (NH4+) into organic compounds is via |
| A. | reduction of pyruvate or alpha-ketoglutarate by enzymes |
| B. | atmospheric nitrogen fixation |
| C. | oxidation of pyruvate |
| D. | all of these |
| Answer» B. atmospheric nitrogen fixation | |
| 75. |
The mechanism of passive or facilitated diffusion require |
| A. | metabolic energy |
| B. | concentration of solute against an electrochemical gradient |
| C. | accumulation of solute against an electrochemical gradient |
| D. | accumulation or concentration of solute against an electrochemical gradient |
| Answer» B. concentration of solute against an electrochemical gradient | |
| 76. |
Which one of the following is not produced in any of the steps of glycolysis? |
| A. | NAD+ |
| B. | NADH |
| C. | ADP |
| D. | ATP |
| Answer» B. NADH | |
| 77. |
The chlorophyll molecules used by eucaryotes and cyanobacteria absorb radiant energy in the____________portion(s) of the visible spectrum. |
| A. | red |
| B. | green |
| C. | red and blue |
| D. | green and ultraviolet |
| Answer» D. green and ultraviolet | |
| 78. |
How many molecules of carbon dioxide will be given off during ten turns of the Krebs cycle? |
| A. | 10 |
| B. | 20 |
| C. | 30 |
| D. | 40 |
| Answer» C. 30 | |
| 79. |
If radioactive bicarbonate was supplied to bacterial cells, which were actively synthesizing fatty acids, it is expected to find the bulk of the radioactivity in |
| A. | cellular bicarbonate |
| B. | the fatty acids |
| C. | the cytoplasmic membrane |
| D. | nucleic acids |
| Answer» B. the fatty acids | |
| 80. |
Which of the following replication methods leads to the production of two circular daughter chromosomes? |
| A. | Theta mode |
| B. | Sigma mode |
| C. | Linear mode |
| D. | Rolling circle method |
| Answer» B. Sigma mode | |
| 81. |
In lactic acid fermentation, the final electron acceptor would be |
| A. | fructose |
| B. | pyruvate |
| C. | glucose |
| D. | acetyl-CoA |
| Answer» C. glucose | |
| 82. |
The amino acids for protein synthesis is activated by the enzyme ______________ |
| A. | rna synthetase |
| B. | aminoacyl-tRNA synthetase |
| C. | tRNA synthetase |
| D. | aminoacyl-mRNA synthetase |
| Answer» C. tRNA synthetase | |
| 83. |
Radioisotopes are frequently used in the study of cells. Assume a culture of E. coli is grown in a culture medium containing radioactive phosphorous. At the end of 48 hours, it is expected to find the radioactive label located in |
| A. | enzymes |
| B. | RNA |
| C. | phospholipids |
| D. | all of these |
| Answer» E. | |
| 84. |
Which of the following bacteria can synthesize all of the amino acids required for protein synthesis? |
| A. | E.coli |
| B. | Lactobacillus bravis |
| C. | Saccharomyces cerevisiae |
| D. | Bacillus subtilis |
| Answer» B. Lactobacillus bravis | |
| 85. |
Basal metabolic rate shall be measured while a person is |
| A. | jogging |
| B. | going to work |
| C. | resting |
| D. | sweating |
| Answer» D. sweating | |
| 86. |
During the reduction phase of the Calvin cycle, phosphoglyceric acid is reduced to______utilizing________as the reduction source. |
| A. | phosphoglyceraldehyde; NADPH+H+ |
| B. | phosphoglyceraldehyde; NADH+H+ |
| C. | ribulose 1,5 - bisphosphate; NADH+H+ |
| D. | pyruvic acid; NADPH+H+ |
| Answer» B. phosphoglyceraldehyde; NADH+H+ | |
| 87. |
Bacteriochlorophyll differs from chlorophyll in what way? |
| A. | The chelated metal in bacteriochlorophyll is not Mg |
| B. | There are chemical differences between the two chlorophyll in their side (R) groups |
| C. | They have different absorption spectra |
| D. | Both (b) and (c) |
| Answer» E. | |
| 88. |
Which of the following best explains about the usefulness of the production of ethanol in yeast cells under anaerobic conditions? |
| A. | Ethanol keeps the electron transport system functioning |
| B. | Yeast would be unable to activate the enzymes of the Krebs cycle without ethanol |
| C. | The process generates oxygen, which is required for glycolysis |
| D. | The process regenerates NAD+, which is required for glycolysis |
| Answer» E. | |
| 89. |
Eukaryotes replicate their DNA from one origin or growing point per molecule. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 90. |
Which of the following RNA constitutes 90 percent of the total cellular RNA? |
| A. | rRNA |
| B. | tRNA |
| C. | mRNA |
| D. | hnRNA |
| Answer» B. tRNA | |
| 91. |
Digestive reactions where large molecules are broken down into smaller ones are referred as |
| A. | anabolism |
| B. | catabolism |
| C. | metabolism |
| D. | biosynthesis |
| Answer» C. metabolism | |
| 92. |
Which of the following is responsible for phosphate solubilization? |
| A. | Streptococcus |
| B. | Streptomyces |
| C. | Bacillus |
| D. | Clostridium |
| Answer» D. Clostridium | |
| 93. |
The number of ATP molecules produced from one glucose molecule by a bacterium producing lactic acid is |
| A. | greater than producing ethanol |
| B. | lesser than producing ethanol |
| C. | approximately equal to producing ethanol |
| D. | none of these |
| Answer» D. none of these | |
| 94. |
Which of the following nucleoside diphosphates is used most often in carbohydrate anabolism? |
| A. | Uridine diphosphate |
| B. | Adenosine diphosphate |
| C. | Guanine diphosphate |
| D. | Thymine diphosphate |
| Answer» B. Adenosine diphosphate | |
| 95. |
Xylulose-5-phosphate is an intermediate in ___________ |
| A. | Glycolysis |
| B. | Pentose Phosphate Pathway |
| C. | Entner-Doudoroff Pathway |
| D. | Fermentation |
| Answer» C. Entner-Doudoroff Pathway | |
| 96. |
Entner-Doudoroff pathway takes place only in procaryotes. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» B. False | |
| 97. |
Stickland reaction is the alternative name for ________ |
| A. | Lactic acid fermentation |
| B. | Alcoholic fermentation |
| C. | Mixed acid fermentation |
| D. | Amino acid fermentation |
| Answer» E. | |
| 98. |
Which of the following are propionic acid bacteria? |
| A. | Streptococcus |
| B. | Acetobacter |
| C. | Clostridium |
| D. | Veillonella |
| Answer» E. | |
| 99. |
The TCA Cycle is an _____________ pathway. |
| A. | catabolic |
| B. | anabolic |
| C. | amphibolic |
| D. | respiratory |
| Answer» D. respiratory | |
| 100. |
What is the other name of glycolysis? |
| A. | PPP cycle |
| B. | TCA cycle |
| C. | C4 cycle |
| D. | EMP pathway |
| Answer» E. | |