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100 Important Biology Solved MCQ’s

1. Which of the following statement is incorrect regarding enzyme?

(A) They catalyze a chemical reaction without being utilized


(B) They without their cofactor are called apoenzyme


(C) Some of them consist solely of protein, with no non-protein part


(D) All enzymes are fibrous proteins



2. ________ coined the term CELL:

(A) Robert Hook


(B) Louis Pasteur


(C) Theodor Schwann and Schleiden


(D) Both A & B



3. _________ has the enzymes controlling respiration:

(A) Chloroplast


(B) Mitochondria


(C) Ribosome


(D) Nucleus



4. Who hypothesized that new cells are formed from the previously existing living cell?

(A) Louis Pasteur


(B) Theodor Schwann and Schleiden


(C) Rudolph Virchow


(D) None of the above



5. What is an activated enzyme consisting of a polypeptide and a cofactor called?

(A) Holoenzyme


(B) Apoenzyme


(C) Activated enzyme


(D) Both A & C



6. What is the resolution power of a compound microscope?

(A) 2.0 um


(B) 24 A


(C) 24 um


(D) 2-4 A



7. _____________ forms the raw material for coenzymes:

(A) Metals


(B) Proteins


(C) Vitamins


(D) Carbohydrates



8. Which of the following is the first layer of the cell wall formed?

(A) Secondary wall


(B) None of these


(C) Middle lamella


(D) Primary wall



9. The activation energy of a chemical reaction ____________ by enzymes:

(A) Doesn’t affect


(B) Decreases


(C) Increases


(D) Increases or decreases depending upon individual enzyme



10. ___________ has cellulose as the major component:

(A) Middle lamella


(B) Primary wall


(C) Secondary wall


(D) None of the above



11. __________ is a cofactor made of inorganic ion which is detachable:

(A) Activator


(B) Prosthetic group


(C) Coenzyme


(D) None of the above



12. ___________ is the factory of ribosomal synthesis:

(A) Nucleus


(B) Endoplasmic reticulum


(C) Cytoplasm


(D) Nucleolus



13. ______________ is a three-dimensional cavity bearing a specific charge by which the enzyme reacts with its substrate:

(A) Catalytic site


(B) Allosteric site


(C) Binding site


(D) Active site



14. What are autophagosomes?

(A) Lysosomes which help in extracellular digestion


(B) Those lysosomes which eat parts of their own cells to generate energy


(C) Those lysosomes which eat old and worn out cellular organelles


(D) Both B & C



15. Which of the following step causes the activation of the catalytic site of an enzyme?

(A) Change in the charge of the active site


(B) Change in temperature


(C) Formation of the enzyme-substrate complex


(D) Change in pH of the surroundings



16. What is the percentage of proteins in the cell membrane?

(A) 100-120%


(B) 80-100%


(C) 60-80%


(D) 120-140%



17. Who proposed Lock and Key model?

(A) Robin Williams


(B) Emil Fischer


(C) Rudolph Virchow


(D) Koshland



18. Centrioles are composed of ______ triplets of microtubules:

(A) 9


(B) 2


(C) 6


(D) 12



19. Which of the following is incorrect about Lock and Key model?

(A) The active site does not change before, during, or even after the reaction


(B) A specific enzyme can transform only a specific substrate


(C) It explains the mechanism of every chemical reaction


(D) The active site of an enzyme is a non-flexible structure



20. Ribosomes + mRNA:

(A) Polysome


(B) Polysome


(C) both a and b


(D) None of the above



21. Which statement is incorrect in this respect: The rate of a reaction is directly proportional to the concentration of an enzyme?

(A) If the concentration is doubled the rate will become two fold


(B) Increase in enzyme molecule increases the available active sites


(C) None of the above


(D) This relation is for an unlimited time period with unlimited enzyme concentration



22. The maturing face in Golgi apparatus is:

(A) Spherical


(B) Biconcave


(C) Convex


(D) Concave



23. If the concentration of the enzyme is kept constant, and the amount of substrate is increased, a point is reached where an increase in substrate’s concentration doesn’t affect the reaction rate because of:

(A) The rate of reaction is indirectly proportional to substrate concentration at this point


(B) Enzymes get denatured at higher substrate conc


(C) All the active sites on enzyme molecule are occupied


(D) None of the above



24. Chlorophyll is a/an __________ molecule:

(A) Anionic


(B) Cationic


(C) Inorganic


(D) Organic



25. If more substrate to the already occurring enzymatic reaction is added, more enzyme activity is seen because:

(A) There is probably more product present than there is either substrate or enzyme


(B) There is probably more substrate present than there is the enzyme


(C) The enzyme-substrate complex is probably failing to form during the reaction


(D) There is probably more enzyme available than there is a substrate



26. Where are ribosomes assembled?

(A) DNA


(B) Nucleolus


(C) RNA


(D) Nucleus



27. If more substrate to already occurring enzymatic reaction is added, and there is no effect on the rate of the reaction, what is the form given to this situation?

(A) Composition


(B) Saturation


(C) Inhibition


(D) Denaturation



28. __________ is not present in mitochondria:

(A) Ribosomes


(B) Co-enzymes


(C) Enzymes


(D) Thylakoids



29. The active site of an enzyme:

(A) Forms no chemical bond with the substrate


(B) They are non-specific in their action


(C) Never changes


(D) Determined by the structure and the specificity of the enzyme



30. Chlorophyll molecule contains _______ as central metal ion:

(A) Zn²⁺


(B) Cu²⁺


(C) Fe²⁺


(D) Mg²⁺



31. Excessive increase in temperature of the medium causes the enzyme molecule to:

(A) Denatured


(B) Activate


(C) Unaffected


(D) None of the above



32. ___________ impart a red colour to Rose petals:

(A) Leukoplast


(B) Chromoplast


(C) Chloroplast


(D) Chlorophyll



33. The extreme change in pH leads to:

(A) Change in ionization of amino acids at the active site of the enzyme


(B) Increase in the reaction rate


(C) Denaturation of the enzyme


(D) Change in the ionization of the substrate



34. In an RBC, number of nuclear pores are:

(A) 20,000


(B) 1000


(C) 500


(D) 3-4



35. In a human body, optimal temperature of enzymes present are:

(A) 30 degree-Celsius


(B) 40 degree-Celsius


(C) 37 degree-Celsius


(D) 45 degree-Celsius



36. Solanum tuberosum is the scientific name of __________:

(A) Tomato


(B) Potato


(C) Onion


(D) Amaltas



37. A chemical substance which can react (in place of the substrate) with the enzyme but is not transformed into product/s and thus blocks the active site temporarily or permanently is called:

(A) Blocker


(B) Cofactor


(C) Co-enzyme


(D) Inhibitor



38. Allium cepa is the scientific name of __________:

(A) Onion


(B) Tomato


(C) Potato


(D) Amaltas



39. Inhibitors which block the enzyme by forming a weak bond are known as:

(A) Both B & C


(B) Competitive inhibitors


(C) Non-competitive inhibitors


(D) Irreversible inhibitors



40. Who proposed five kingdom classification?

(A) E-Chatton


(B) Lynn Margulis and Karlene Schwartz


(C) Carlos Linnaeus


(D) Robert Whittaker



41. A substance which binds at the active site of the enzyme but doesn’t result in the formation of the products is called:

(A) Competitive inhibitor


(B) Non-competitive inhibitor


(C) Reversible inhibitor


(D) Irreversible inhibitor



42. From which kingdom Amoeba belongs to?

(A) Monera


(B) Plantae


(C) Prokaryotae


(D) Protista



43. The structure of an enzyme is altered by ___________:

(A) Competitive inhibitor


(B) Reversible inhibitor


(C) Irreversible inhibitor


(D) Non-competitive inhibitor



44. Kingdom Monera is also known as:

(A) Prokaryotae


(B) Protoctista


(C) Archae


(D) None of the above



45. Malonic acid is an example of ___________:

(A) Irreversible inhibitor


(B) Reversible inhibitor


(C) Competitive inhibitor


(D) Non-competitive inhibitor



46. What is the coat that encloses RNA or DNA of viruses?

(A) Lipid


(B) DNA


(C) Protein


(D) Carbohydrate



47. If enzyme concentration is low compared to the substrate, and pH and temperature values meet the requirement, which of the following will increase the rate of reaction?

(A) Increase in pH


(B) Increase in concentration of enzyme


(C) Increase in temperature


(D) Increase in concentration of substrate



48. Who discovered the Vaccine?

(A) Ivanowski


(B) Stanely


(C) Edward Jenner


(D) Louis Pasteur



49. ___________ is not present in all the bacteria:

(A) Capsule


(B) Ribosomes


(C) Cell membrane


(D) Chromatin bodies



50. What is the size of the smallest virus?

(A) 8mm


(B) 4mm


(C) 16mm


(D) 20mm



51. How many postulates does the Germ Theory of Disease have?

(A) 16


(B) 10


(C) 15


(D) 4



52. Protein subunits of the capsid, called capsomeres, are characteristic of each virus. Their number in Herpes virus is:

(A) 162


(B) 190


(C) 184


(D) 178



53. The first bacterium isolated was _________:

(A) Bacillus


(B) Spirochete


(C) Coccus


(D) Vibrio



54. What is the size of the poxvirus?

(A) 275 nm


(B) 260 nm


(C) 270 nm


(D) 250 nm



55. ___________ bacteria are rigid, spiral, and thick:

(A) Spirochete


(B) Spirillum


(C) Vibrio


(D) Coccus



56. How many times are viruses smaller than bacteria?

(A) 10-1000 times


(B) 10-100 times


(C) 100-1000 times


(D) 1000-10000 times



57. What is a group of 8 cocci called?

(A) Tetrad


(B) Sarcina


(C) Diplococci


(D) Octococci



58. What is a virion?

(A) Viral lysozyme


(B) Viral gene


(C) Virus


(D) Viral protein



59. _________ bacteria do not have flagella commonly:

(A) Streptobacilli


(B) Vibrio


(C) Cocci


(D) Bacilli



60. Temperate phage may exist as ________:

(A) Virion


(B) Retrovirus


(C) Capsid


(D) Prophage



61. From where do flagella originate?

(A) Capsule


(B) Basal body


(C) Cell membrane


(D) Cell wall



62. ___________ is an RNA virus:

(A) Influenza virus


(B) Pox-virus


(C) HBV


(D) Herpes simplex



63. Cell wall is absent in ___________:

(A) Mycobacterium


(B) Mycoplasma


(C) Cocci


(D) Bacilli



64. Which is the smallest known virus?

(A) Pox virus


(B) Polio virus


(C) Hepatitis virus


(D) Retrovirus



65. Gram-positive bacteria appear:

(A) Pink


(B) Purple


(C) Blue


(D) Yellow



66. Hepatitis A mode of transmission is:

(A) Sexual contact


(B) Faeco-oral


(C) Serum


(D) None of the above



67. __________ is the common waste material in bacteria:

(A) Glycogen


(B) Urea


(C) Ammonia


(D) Lactic acid



68. For which no preventive vaccine is available?

(A) HAV


(B) HEV


(C) HCV


(D) HBV



69. E. Coli is an example of __________:

(A) Aerobic bacteria


(B) Microaerophilic


(C) Facultative bacteria


(D) Anaerobic bacteria



70. How many phyla does Kingdom Protista include?

(A) 22


(B) 23


(C) 27


(D) 28



71. Spirochete is an example of ___________:

(A) Anaerobic bacteria


(B) Microaerophilic


(C) Aerobic bacteria


(D) Facultative bacteria



72. Which has glassy shells?

(A) Both A & B


(B) Radiolarians


(C) Forams


(D) None of the above



73. The vaccine against anthrax was developed by:

(A) None of the above


(B) Alexander Fleming


(C) Edward Jenner


(D) Louis Pasteur



74. Mostly photosynthesis on earth is carried by:

(A) Angiosperms


(B) Kelps


(C) Algae


(D) Gymnosperms



75. Cyanobacteria is reproduced by:

(A) Meiosis


(B) Conjugation


(C) Mitosis


(D) Binary fission



76. The second name of brown algae is:

(A) Pyrrophyta


(B) Phaeophyta


(C) Chrysoprase


(D) Rhodophyta



77. What is incorrect about plants?

(A) Are heterotrophs


(B) Non-motile organisms


(C) All are eukaryotes


(D) They are multicellular



78. Another name of golden algae is:

(A) Pyrrophyta


(B) Rhodophyta


(C) Phaeophyta


(D) Chrysophyta



79. What is the reason Bryophytes are called amphibians of the plant world?

(A) Amphibians have a close relation with bryophytes in their habitat


(B) Bryophytes like amphibian ancestors are one of the most primitive organisms in this world


(C) Bryophytes like amphibians live in damp shady places and close to the water body


(D) None of the above



80. Most of the dinoflagellates are ___________:

(A) Zooflagellates


(B) Unicellular


(C) Multicellular


(D) All of these



81. In which sub-class are Hornworts included?

(A) Hepaticopsida


(B) Psilopsida


(C) Anthoceropsida


(D) Bryopsida



82. The main energy stores in chlorophytes are:

(A) Glycogen


(B) Cellulose


(C) Starch


(D) None of the above



83. Horsetails are included in ____________ class:

(A) Psilopsida


(B) Pteropsida


(C) Lycopsida


(D) Sphenopeida



84. Spores produced by slime molds are _________:

(A) Haploid


(B) Triploid


(C) Diploid


(D) None of the above



85. Archegonia and Antheridia are born on ____________ in bryophytes:

(A) Sporophyte


(B) Gametophyte


(C) Both A & B


(D) None of the above



86. Aschelminthes is also called:

(A) Protozoans


(B) Protoctist ancestors


(C) Nematodes


(D) Eumatazoa



87. Where does fertilization take place in bryophytes?

(A) Water


(B) Ovule


(C) Antheridia


(D) Archegonia



88. Which is not included in Protostomes?

(A) Hemichordates


(B) Molluscs


(C) Arthropods


(D) Annelids



89. Which is incorrect about alternation of generation in bryophytes?

(A) It involves alternation of morphologically different generations


(B) Spore formation occurs through meiosis


(C) Both the gametophyte and sporophyte are haploid generations, thus can produce haploid gametes to continue the diploid number on fertilization


(D) Their gametophyte is independent while the sporophyte depends upon the gametophyte for nutrition



90. Which is not a coelomate?

(A) Hemichordates


(B) Aschelminthes


(C) Deuterostomes


(D) Protostomes



91. Antherozoids, the male gamete in bryophytes, are attracted to Archegonium (i.e., the female sex organ) by:

(A) Geotropic phenomenon


(B) Phototactic phenomenon


(C) Chemotropic movement


(D) Chemotactic phenomenon



92. The name animal is derived from the word __________:

(A) Aname


(B) Anima


(C) Anemia


(D) None of the above



93. __________ bryophytes are the simplest ones:

(A) Funaria


(B) Polytrichum


(C) Porella


(D) Anthocerus



94. Which is not the characteristic of Kingdom Animalia?

(A) It is the largest kingdom


(B) All animals develop from dissimilar gametes, i.e., large sperm and small egg


(C) All animals are ingestive heterotrophs


(D) All animals are eukaryotes



95. In liverworts, the zygote formed is:

(A) Multinucleate


(B) Unicellular


(C) Multicellular


(D) None of the above



96. Which of the following is true about the class Psilopsida?

(A) They have true leaves


(B) They have vascular tissues


(C) They do not have leaves and roots


(D) They are found in marine environments



97. The common name of the organism that produces a “black mold” in food is:

(A) Penicillium


(B) Rhizopus


(C) Aspergillus


(D) Cladosporium



98. The most primitive group of seed plants are:

(A) Angiosperms


(B) Cycads


(C) Conifers


(D) Gymnosperms



99. Xylem vessels are:

(A) Alive at maturity


(B) Only present in angiosperms


(C) Dead at maturity


(D) Only present in gymnosperms



100. Which group of plants shows the greatest variety of reproductive structures?

(A) Algae


(B) Gymnosperms


(C) Angiosperms


(D) Mosses




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