100 Important Biology Solved MCQ’s

100 Important Biology Solved MCQ’s

If you have a plan to appear in any kind of exam in Biology, then these 100  important Biology MCQ’s will help you in your preparation. So best of luck for your exam.

1. Which of the following statement is incorrect regarding enzyme?
A. All enzymes are fibrous proteins
B. They without their cofactor are called apoenzyme
C. Some of them consist solely of protein, with no non-protein part
D. They catalyze a chemical reaction without being utilized

Answer - Click Here:
A

2. ________ coined the term CELL:
A. Robert Hook
B. Louis Pasteur
C. Theodor Schwann and Schleiden
D. Both A & B

Answer - Click Here:
A

3. _________ has the enzymes controlling respiration:
A. Chloroplast
B. Nucleus
C. Ribosome
D. Mitochondria

Answer - Click Here:
D

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

Answer - Click Here:
C

5. What is an activated enzyme consisting of a polypeptide and a cofactor called?
A. Activated enzyme
B. Apoenzyme
C. Holoenzyme
D. Both A & C

Answer - Click Here:
D

6. What is the resolution power of a compound microscope?
A. 24 um
B. 24 A
C. 2.0 um
D. 2-4 A

Answer - Click Here:
C

7. _____________ forms the raw material for coenzymes:
A. Vitamins
B. Proteins
C. Metals
D. Carbohydrates

Answer - Click Here:
A

8. Which of the following is the first layer of the cell wall formed?
A. Secondary wall
B. Primary wall
C. Middle lamella
D. None of these

Answer - Click Here:
B

9. The activation energy of a chemical reaction ____________ by enzymes:
A. Doesn’t effect
B. Increases or decreases depending upon individual enzyme
C. Increases
D. Decreases

Answer - Click Here:
D

10. ___________ has cellulose as the major component:
A. Middle lamella
B. Primary wall
C. Secondary wall
D. None of the above

Answer - Click Here:
B

11. __________ is a cofactor made of inorganic ion which is detachable:
A. Activator
B. Prosthetic group
C. Coenzyme
D. None of the above

Answer - Click Here:
A

12. ___________ is the factory of ribosomal synthesis:
A. Nucleus
B. Endoplasmic reticulum
C. Nucleolus
D. Cytoplasm

Answer - Click Here:
C

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. Active site
D. Binding site

Answer - Click Here:
C

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

Answer - Click Here:
D

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. Formation of enzyme-substrate complex
C. Change in temperature
D. Change in pH of the surroundings

Answer - Click Here:
B

16. What is the percentage of proteins in the cell membrane?
A. 60-80%
B. 80-100%
C. 100-120%
D. 120-140%

Answer - Click Here:
A

17. Who proposed Lock and Key model?
A. Robin Williams
B. Rudolph Virchow
C. Emil Fischer
D. Koshland

Answer - Click Here:
C

18. Centrioles are composed of ______ triplets of microtubules:
A. 12
B. 2
C. 6
D. 9

Answer - Click Here:
D

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. It explains the mechanism of every chemical reaction
C. A specific enzyme can transform only a specific substrate
D. The active site of an enzyme is a non-flexible structure

Answer - Click Here:
B

20. Ribosomes + mRNA:
A. Polysome
B. Polysome
C. Pylosome
D. None of the above

Answer - Click Here:
C

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. This relation is for an unlimited time period with unlimited enzyme concentration
D. None of the above

Answer - Click Here:
C

22. The maturing face in Golgi apparatus is:
A. Spherical
B. Biconcave
C. Convex
D. Concave

Answer - Click Here:
D

23. If the concentration of 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. All the active sites on enzyme molecule are occupied
B. Enzymes get denaturated at higher substrate conc
C. The rate of reaction is indirectly proportional to substrate concentration at this point
D. None of the above

Answer - Click Here:
A

24. Chlorophyll is a/an __________ molecule:
A. Anionic
B. Organic
C. Inorganic
D. Cationic

Answer - Click Here:
B

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. The enzyme-substrate complex is probably failing to form during the reaction
C. There is probably more substrate present than there is the enzyme
D. There is probably more enzyme available than there is a substrate

Answer - Click Here:
D

26. Where are ribosomes assembled?
A. DNA
B. RNA
C. Nucleolus
D. Nucleus

Answer - Click Here:
C

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. Inhibition
C. Saturation
D. Denaturation

Answer - Click Here:
C

28. __________ is not present in mitochondria:
A. Ribosomes
B. Thylakoids
C. Enzymes
D. Co-enzymes

Answer - Click Here:
B

29. The active site of an enzyme:
A. Determined by the structure and the specificity of the enzyme
B. They are non-specific in their action
C. Never changes
D. Forms no chemical bond with the substrate

Answer - Click Here:
A

30. Chlorophyll molecule contains _______ as central metal ion:
A. Zn2+
B. Cu+2
C. Fe2+
D. Mg2+

Answer - Click Here:
D

31. Excessive increase in temperature of the medium causes the enzyme molecule to:
A. Denatured
B. Activate
C. Unaffected
D. None of the above

Answer - Click Here:
A

32. ___________ impart a red colour to Rose petals:
A. Chromoplast
B. Leukoplast
C. Chloroplast
D. Chlorophyll

Answer - Click Here:
A

33. The extreme change in pH leads to:
A. Denaturation of the enzyme
B. Increase in the reaction rate
C. Change in ionization of amino acids at the active site of the enzyme
D. Change in the ionization of the substrate

Answer - Click Here:
C

34. In an RBC, number of nuclear pores are:
A. 20,000
B. 1000
C. 500
D. 3-4

Answer - Click Here:
D

35. In a human body, optimal temperature of enzymes present are:
A. 30 degree-Celcius
B. 37 degree-Celcius
C. 40 degree-Celcius
D. 45 degree-Celcius

Answer - Click Here:
B

36. Solanum tuberosum is the scientific name of __________:
A. Potato
B. Tomato
C. Onion
D. Amaltas

Answer - Click Here:
A

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. Inhibitor
B. Cofactor
C. Co-enzyme
D. Blocker

Answer - Click Here:
A

38. Allium cepa is the scientific name of __________:
A. Potato
B. Tomato
C. Onion
D. Amaltas

Answer - Click Here:
D

39. Inhibitors which block the enzyme by forming a weak bond are known as:
A. Irreversible inhibitors
B. Competitive inhibitors
C. Non-competitive inhibitors
D. Both B & C

Answer - Click Here:
D

40. Who proposed five kingdom classification?
A. Robert Whittaker
B. Lynn Margulis and Karlene Schwartz
C. Carlos Linnaeus
D. E-Chatton

Answer - Click Here:
A

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

Answer - Click Here:
B

42. From which kingdom Amoeba belongs to?
A. Monera
B. Protista
C. Prokaryotae
D. Plantae

Answer - Click Here:
B

43. The structure of an enzyme is altered by ___________:
A. Competitive inhibitor
B. Reversible inhibitor
C. Irreversible inhibitor
D. Non-competitive inhibitor

Answer - Click Here:
D

44. Kingdom Monera is also known as:
A. Archae
B. Protoctista
C. Prokaryotae
D. None of the above

Answer - Click Here:
C

45. Malonic acid is an example of ___________:
A. Competitive inhibitor
B. Reversible inhibitor
C. Irreversible inhibitor
D. Non-competitive inhibitor

Answer - Click Here:
A

46. RNA or DNA of viruses is enclosed in which coat?
A. Lipid
B. DNA
C. Protein
D. Carbohydrate

Answer - Click Here:
C

47. If enzyme concentration is low than the substrate, pH and temperature values are equal to requirement then which of the following will increase the rate of reaction?
A. Increase in pH
B. Increase in temperature
C. Increase in concentration of enzyme
D. Increase in concentration of substrate

Answer - Click Here:
C

48. Who discovered the Vaccine?
A. Ivanowski
B. Stanely
C. Louis Pasteur
D. Edward Jenner

Answer - Click Here:
D

49. ___________ is not present in all the bacteria:
A. Ribosomes
B. Capsule
C. Cell membrane
D. Chromatin bodies

Answer - Click Here:
B

50. What is the size of a smallest virus?
A. 4mm
B. 8mm
C. 16mm
D. 20mm

Answer - Click Here:
D

51. How many postulates do Germ theory of disease have?
A. 4
B. 10
C. 15
D. 16

Answer - Click Here:
A

52: Proteins subunits of the capsid is called the capsomeres, is a characteristic of each virus. Their number in Herpes virus is:
A. 162
B. 178
C. 184
D. 190

Answer - Click Here:
A

53. The first bacterium isolated was _________:
A. Vibrio
B. Spirochete
C. Coccus
D. Bacillus

Answer - Click Here:
D

54. What is the size of poxvirus?
A. 250 nm
B. 260 nm
C. 270 nm
D. 275 nm

Answer - Click Here:
A

55. ___________ bacteria are rigid, spiral and thick:
A. Spirochete
B. Coccus
C. Vibrio
D. Spirillum

Answer - Click Here:
D

56. How many times the virus are smaller than bacteria?
A. 10-100 times
B. 10-1000 times
C. 100-1000 times
D. 1000-10000 times

Answer - Click Here:
B

57. What is a group of 8 cocci called?
A. Tetrad
B. Sarcina
C. Diplococci
D. Octococci

Answer - Click Here:
B

58. What is a virion?
A. Viral lysozyme
B. Viral gene
C. Virus
D. Viral protein

Answer - Click Here:
C

59. _________ bacteria do not have flagella commonly:
A. Streptobacilli
B. Vibrio
C. Cocci
D. Bacilli

Answer - Click Here:
C

60. Temperate phage may exist as ________:
A. Viron
B. Retrovirus
C. Prophage
D. Capsid

Answer - Click Here:
C

61. From where flagella originate?
A. Capsule
B. Basal body
C. Cell membrane
D. Cell wall

Answer - Click Here:
B

62. ___________ is an RNA virus:
A. HBV
B. Pox-virus
C. Influenza virus
D. Herpes simplex

Answer - Click Here:
C

63. Cell wall is absent in ___________:
A. Mycobacterium
B. Mycoplasma
C. Cocci
D. Bacilli

Answer - Click Here:
B

64. Which is the smallest known virus?
A. Polio virus
B. Pox virus
C. Hepatitis virus
D. Retrovirus

Answer - Click Here:
A

65. Gram-positive bacteria appear:
A. Pink
B. Blue
C. Purple
D. Yellow

Answer - Click Here:
C

66. Hepatitis A mode of transmission is:
A. Sexual contact
B. Serum
C. Faeco-oral
D. None of the above

Answer - Click Here:
C

67. __________ is the common waste material in bacteria:
A. Ammonia
B. Urea
C. Glycogen
D. Lactic acid

Answer - Click Here:
D

68. For which no preventive vaccine is available?
A. HCV
B. HEV
C. HAV
D. HBV

Answer - Click Here:
A

69. E. Coli is an example of __________:
A. Facultative bacteria
B. Microaerophilic
C. Aerobic bacteria
D. Anaerobic bacteria

Answer - Click Here:
A

70. How many phyla do Kingdom Protista include?
A. 22
B. 23
C. 27
D. 28

Answer - Click Here:
C

71. Spirochete is an example of ___________:
A. Facultative bacteria
B. Microaerophilic
C. Aerobic bacteria
D. Anaerobic bacteria

Answer - Click Here:
D

72. Which has glassy shells?
A. Forams
B. Radiolarians
C. Both A & B
D. None of the above

Answer - Click Here:
B

73. The vaccine against anthrax was developed by:
A. Louis Pasteur
B. Alexander Fleming
C. Edward Jenner
D. None of the above

Answer - Click Here:
A

74. Mostly photosynthesis on earth is carried by:
A. Angiosperms
B. Algae
C. Kelps
D. Gymnosperms

Answer - Click Here:
B

75. Cyanobacteria is reproduced by:
A. Meiosis
B. Conjugation
C. Binary fission
D. Mitosis

Answer - Click Here:
C

76. The second name of brown algae is:
A. Pyrrophyta
B. Chrysoprase
C. Phaeophyta
D. Rhodophyta

Answer - Click Here:
C

77. What is incorrect about plants?
A. Non-motile organisms
B. Are heterotrophs
C. All are eukaryotes
D. They are multicellular

Answer - Click Here:
B

78. Another name of golden algae is:
A. Pyrrophyta
B. Rhodophyta
C. Chrysophyta
D. Phaeophyta

Answer - Click Here:
C

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 amphibian live in damp shady places and close to the water body
D. None of the above

Answer - Click Here:
C

80. Most of the dinoflagellates are ___________:
A. Zooflagellates
B. Unicellular
C. Multicellular
D. All of these

Answer - Click Here:
B

81: In which sub-class Hornworts are included?
A. Hepaticopsida
B. Psilopsida
C. Anthoceropsida
D. Bryopsido

Answer - Click Here:
C

82. The main energy stones in chlorophytes are:
A. Glycogen
B. Cellulose
C. Starch
D. None of the above

Answer - Click Here:
C

83. Horsetails are included in ____________ class:
A. Psilopsida
B. Pteropsida
C. Sphenopeida
D. Lycopsida

Answer - Click Here:
C

84. Spores produced by slime molds are _________:
A. Triploid
B. Haploid
C. Diploid
D. None of the above

Answer - Click Here:
B

85. Archegonia and Antheridia are born on ____________ in bryophytes:
A. Gametophyte
B. Sporophyte
C. Both A & B
D. None of the above

Answer - Click Here:
A

86. Aschelminthes is also called:
A. Nematodes
B. Protoctist ancestors
C. Protozoans
D. Eumatazoa

Answer - Click Here:
A

87. Where does fertilization take place in bryophytes?
A. Water
B. Ovule
C. Antheridia
D. Archegonia

Answer - Click Here:
D

88. Which is not included in Protostomes?
A. Annelids
B. Molluscs
C. Arthropods
D. Hemichordates

Answer - Click Here:
D

89. Which is incorrect about alternation of generation in bryophytes?
A. Both the gametophyte and sporophytes are haploid generations, thus can produce haploids gametes to continue the diploid number on fertilization
B. Spore formation occurs through meiosis
C. It involves alternation of morphologically different generations
D. Their gametophyte is independent while sporophyte depends upon gametophyte for nutrition

Answer - Click Here:
A

90. Which is not a coelomate?
A. Hemichordates
B. Ascheldiminthes
C. Deuterostomes
D. Proteosomes

Answer - Click Here:
B

91. Antherozoids, the male gamete in bryophytes, are attracted to Archegonium i.e., female sex organ by:
A. Geotropic phenomenon
B. Chemotropic movement
C. Phototactic phenomenon
D. Chemotactic phenomenon

Answer - Click Here:
D

92. The name animal is derived from the word __________:
A. Aname
B. Anima
C. Anemia
D. None of the above

Answer - Click Here:
B

93. __________ bryophytes are the simplest one:
A. Anthocerus
B. Polytrichum
C. Porella
D. Funaria

Answer - Click Here:
C

94. Which is not the characteristic of Kingdom Animalia?
A. All animals develop from the dissimilar gametes i.e. large sperm and small egg
B. It is the largest kingdom
C. All animals are ingestive heterotrophs
D. All animals are eukaryotes

Answer - Click Here:
A

95. In liverworts, the zygote formed is:
A. Multinucleate
B. Unicellular
C. Multicellular
D. None of the above

Answer - Click Here:
B

96. The radial symmetry is found in the animals of __________:
A. Cnidaria
B. Protozoa
C. Porifera
D. All of these

Answer - Click Here:
A

97. Sporophyte is _________:
A. Diploid
B. Polyploidy
C. Monoploid
D. Haploid

Answer - Click Here:
A

98. All the animals of the grade radiata are:
A. Unicellular
B. Diploblastic
C. Triploblastic
D. All of these

Answer - Click Here:
B

99. Mosses are included in which sub-division?
A. Bryopsida
B. Lycopsida
C. Anthoceropsida
D. Hepaticopsida

Answer - Click Here:
A

100. Both bilateral symmetry and radial is found in the phylum ______________:
A. Echinodermata
B. Protozoa
C. Porifera
D. None of the above

Answer - Click Here:
A

Topic Covered:  100 Important Biology Solved MCQ’s

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