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.
| 1. |
In which of the following phenomenon the end product act as co-repressor and repress the synthesis of metabolic enzymes? |
| A. | Allosteric regulation |
| B. | Feedback repression |
| C. | Feedback inhibition |
| D. | Regulation by phosphorylation |
| Answer» C. Feedback inhibition | |
| 2. |
Name the inhibition where end products of biosynthesis pathway inhibit the activity of the first enzyme? |
| A. | Feedback inhibition |
| B. | Feedback repression |
| C. | Allosteric inhibition |
| D. | Competitive inhibition |
| Answer» B. Feedback repression | |
| 3. |
How many types of protein kinases are there? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 4. |
Protein kinases are responsible for transferring which group? |
| A. | oxygen |
| B. | carbon |
| C. | amino |
| D. | phosphate |
| Answer» E. | |
| 5. |
How many mechanisms exist for altering the shape of an enzyme, playing a role in regulating glucose oxidation? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 6. |
A cell’s reservoir of NADPH represents its _______________ |
| A. | oxidation state |
| B. | oxidation power |
| C. | tensile strength |
| D. | reducing power |
| Answer» E. | |
| 7. |
Yeast cells convert pyruvate to lactate. |
| A. | True |
| B. | False |
| Answer» C. | |
| 8. |
In case of repeated contraction, muscle cells regenerate NAD⁺ by converting pyruvate to _____________ |
| A. | glycogen |
| B. | lactate |
| C. | starch |
| D. | cellulose |
| Answer» C. starch | |
| 9. |
In fermentation, which of the following is regenerated? |
| A. | Starch |
| B. | Oxygen |
| C. | NAD⁺ |
| D. | NADH |
| Answer» D. NADH | |
| 10. |
NAD⁺ can be derived from which vitamin? |
| A. | A |
| B. | C |
| C. | Riboflavin |
| D. | Niacin |
| Answer» E. | |
| 11. |
NAD is a _________ |
| A. | enzyme |
| B. | cofactor |
| C. | protein |
| D. | nucleoside |
| Answer» C. protein | |
| 12. |
Glycolysis begins with which of the following reactions? |
| A. | reduction |
| B. | oxidation |
| C. | phosphorylation |
| D. | acidification |
| Answer» D. acidification | |
| 13. |
The TCA cycle occurs in which region of a prokaryotic cell? |
| A. | cytosol |
| B. | mitochondria |
| C. | ribsomes |
| D. | golgi complex |
| Answer» B. mitochondria | |
| 14. |
How many molecules of ATP are formed per molecule of oxidation of glucose? |
| A. | 12 |
| B. | 24 |
| C. | 36 |
| D. | 48 |
| Answer» D. 48 | |
| 15. |
Anabolic pathways are energy-requiring. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 16. |
Energy released by catabolic pathways is stored in how many forms? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 17. |
Catabolic pathways result in _______________ of the molecules. |
| A. | assembly |
| B. | functionalization |
| C. | conformation |
| D. | disassembly |
| Answer» E. | |
| 18. |
Assimilatory sulfate reduction involves the nucleotide __________ during the incorporation of H2S in the production of __________ . |
| A. | ATP; methionine |
| B. | ATP; cytosine |
| C. | UTP; cytosine |
| D. | GTP; cytosine |
| Answer» C. UTP; cytosine | |
| 19. |
During the carboxylation phase of the Calvin cycle, CO2 combines with |
| A. | ribulose 1,5 - bisphosphate |
| B. | phosphoglyceraldehyde |
| C. | pyruvic acid |
| D. | oxaloacetic acid |
| Answer» B. phosphoglyceraldehyde | |
| 20. |
Transfer RNA is a single chain of ___________ nucleotides. |
| A. | 340 |
| B. | about 100 |
| C. | about 80 |
| D. | 200 |
| Answer» D. 200 | |
| 21. |
The reaction, where small precursor molecules are assembled into larger organic molecules is referred as |
| A. | anabolism |
| B. | catabolism |
| C. | metabolism |
| D. | any of these |
| Answer» B. catabolism | |
| 22. |
Phosphate is considered to restrict the induction of |
| A. | primary metabolites |
| B. | secondary metabolites |
| C. | both (a) and (b) |
| D. | none of these |
| Answer» C. both (a) and (b) | |
| 23. |
Binding proteins for active transport systems of Gram-negative bacteria are associated with ____________ |
| A. | cell membrane |
| B. | cytoplasmic membrane |
| C. | periplasmic space |
| D. | nuclear membrane |
| Answer» D. nuclear membrane | |
| 24. |
Entner-Doudoroff pathway is found in |
| A. | aerobic prokaryotes |
| B. | anaerobic prokaryotes |
| C. | both (a) and (b) |
| D. | aerobic eukaryotes |
| Answer» D. aerobic eukaryotes | |
| 25. |
Bile is carried form gall bladder through bile duct to |
| A. | liver |
| B. | duodenum |
| C. | small intestine |
| D. | pyloric sphincter |
| Answer» C. small intestine | |
| 26. |
The amount of ATP produced by a cell from glucose when metabolizing it by fermentation means is |
| A. | greater than by aerobic metabolism |
| B. | lesser than by aerobic metabolism |
| C. | exactly or approximately equal to by aerobic metabolism |
| D. | none of these |
| Answer» C. exactly or approximately equal to by aerobic metabolism | |
| 27. |
Cold climate vs. tropics, the basal metabolic rate is |
| A. | higher |
| B. | lower |
| C. | constant |
| D. | changes with day and night |
| Answer» B. lower | |
| 28. |
Protein synthesis in bacteria takes place on which of the following organelles? |
| A. | Endoplasmic Reticulum |
| B. | Golgi body |
| C. | Ribosomes |
| D. | Mitochondria |
| Answer» D. Mitochondria | |
| 29. |
The amount of ATP that can be obtained by complete oxidation of a glucose by a bacterium is |
| A. | greater than by a yeast cell |
| B. | lesser than by a yeast cell |
| C. | exactly or approximately equal to by a yeast cell |
| D. | none of these |
| Answer» B. lesser than by a yeast cell | |
| 30. |
Keq is greater than 1.0 depending on which of the following conditions? |
| A. | standard free energy change is negative |
| B. | standard free energy change is positive |
| C. | chemical reaction proceeds in reverse direction |
| D. | products are not formed |
| Answer» B. standard free energy change is positive | |
| 31. |
Which of the following(s) is/are the products of the light reactions of photosynthesis? |
| A. | ATP only |
| B. | NADPH only |
| C. | ATP and O2 only |
| D. | ATP, NADPH, and O2 |
| Answer» E. | |
| 32. |
If the chromosome were extended linearly then it would approximately measure? |
| A. | 13500 micrometre |
| B. | 1000 micrometre |
| C. | 1250 micrometre |
| D. | 500 micrometre |
| Answer» D. 500 micrometre | |
| 33. |
RNAase is a single polypeptide chain of __________ amino acid residues. |
| A. | 2 |
| B. | 350 |
| C. | 4 |
| D. | 124 |
| Answer» E. | |
| 34. |
Incorporation of atmospheric N2to NH4+ occurs via the process of |
| A. | assimilatory nitrate reduction |
| B. | transamination |
| C. | deamination |
| D. | nitrogen fixation |
| Answer» E. | |
| 35. |
The peptidoglycan layer of Staphylococcus aureus consists of a bridge between muramic acid peptides which is composed of? |
| A. | alanine |
| B. | lysine |
| C. | proline |
| D. | gycine |
| Answer» E. | |
| 36. |
Which of the following groups contain(s) many unique coenzymes, such as coenzyme M and coenzyme F420? |
| A. | Sulfate-reducing bacteria |
| B. | Methanotrophs (methane-oxidizing microbes) |
| C. | Methanogens (methane-producing microbes) |
| D. | Acetogens (acetigens; acetate-producing microbes) |
| Answer» D. Acetogens (acetigens; acetate-producing microbes) | |
| 37. |
Basal metabolic rate measures |
| A. | how fast chemical reactions occur |
| B. | the time lapse between eating and passing stool |
| C. | number of enzymes required |
| D. | number of active sites |
| Answer» B. the time lapse between eating and passing stool | |
| 38. |
S,the Svedberg unit is a measure of ____________________________ |
| A. | the size of the ribosome |
| B. | the composition of the ribosome |
| C. | how fast a particle sediments during ultracentrifugation. |
| D. | how the subunits combine in a ribosome |
| Answer» D. how the subunits combine in a ribosome | |
| 39. |
The synthesis of polynucleotide chain of mRNA is catalyzed by the enzyme _____________ |
| A. | RNA helicase |
| B. | RNA polymerase |
| C. | DNA polymerase |
| D. | DNA helicase |
| Answer» C. DNA polymerase | |
| 40. |
Radioisotopes are frequently used in the study of cells. Assume a culture of E. coli is grown in a culture medium containing radioactive sulphur. At the end of 48 hours, it is expected to find the radioactive label located in |
| A. | DNA |
| B. | enzymes |
| C. | RNA |
| D. | all of these |
| Answer» C. RNA | |
| 41. |
In an oxygenic photosynthesis, the green and the purple bacteria do not use which of the following one as an electron source? |
| A. | H2O |
| B. | H2 |
| C. | H2S |
| D. | S (elemental sulphur) |
| Answer» B. H2 | |
| 42. |
Rho factor is a dimeric protein factor. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 43. |
Suppose a eukaryotic cell had a mutation that prevented the production of cytochrome c. As a result of this mutation, which of the following processes would not occur? |
| A. | Cellular respiration |
| B. | Photosynthesis |
| C. | Mitosis |
| D. | Cell wall synthesis |
| Answer» B. Photosynthesis | |
| 44. |
In establishing proton gradient for chemiosmotic ATP generation by aerobic respiration the terminal electron acceptor is |
| A. | nitrate |
| B. | oxygen |
| C. | sulfate |
| D. | CO2 |
| Answer» C. sulfate | |
| 45. |
In aerobic respiration the terminal electron acceptor is oxygen,nitrate,sulphate, etc. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 46. |
When acetate is the sole source of carbon for some microorganisms, the cycle which is used, is called |
| A. | pentose phosphate pathway |
| B. | glycolyic pathway |
| C. | glyoxylate pathway |
| D. | oxaloacetate pathway |
| Answer» D. oxaloacetate pathway | |
| 47. |
The relationship between an oxidation-reduction potential difference and the standard free energy change is (where n is the number of moles of electron transferred, F= Faraday's constant and E°= standard oxidation-reduction potential difference) |
| A. | ΔG° = -nFE° |
| B. | ΔG° = nFE° |
| C. | ΔG° = -nFlnE° |
| D. | ΔG° = nFlnE° |
| Answer» B. ΔG° = nFE° | |
| 48. |
The Lambda Bacteriophage carries out which of the following replication methods? |
| A. | Theta mode |
| B. | Sigma mode |
| C. | Linear mode |
| D. | Does not carry out replication |
| Answer» C. Linear mode | |
| 49. |
Which of the following is accomplished in chemiosmosis? |
| A. | The oxidation of ATP |
| B. | The oxidation of water |
| C. | The oxidation of NADH |
| D. | The oxidation of CO2 |
| Answer» D. The oxidation of CO2 | |
| 50. |
Phosphate regulation has been observed in the production of |
| A. | alkaloids |
| B. | antibiotics |
| C. | gibberelins |
| D. | all of these |
| Answer» E. | |