100 Mcqs

1. The basic unit of life is the:
a) Atom
b) Molecule
c) Cell
d) Tissue

2. Which scientist coined the term “cell”?
a) Robert Brown
b) Rudolf Virchow
c) Robert Hooke
d) Antonie van Leeuwenhoek

3. The cell theory was proposed by:
a) Darwin
b) Mendel
c) Schleiden & Schwann
d) Pasteur

4. Which part controls cellular activities?
a) Ribosome
b) Lysosome
c) Nucleus
d) Golgi apparatus

5. The site of protein synthesis is:
a) Nucleus
b) Lysosome
c) Ribosome
d) Mitochondrion

6. Which organelle generates ATP?
a) Chloroplast
b) Nucleus
c) Mitochondria
d) ER

7. Which cell organelle is responsible for photosynthesis?
a) Mitochondria
b) Chloroplast
c) Peroxisome
d) Golgi

8. The endomembrane system includes all EXCEPT:
a) ER
b) Golgi
c) Lysosome
d) Mitochondria

9. What is the function of the rough ER?
a) Lipid synthesis
b) Protein synthesis
c) DNA replication
d) Detoxification

10. Smooth ER is involved in:
a) Protein synthesis
b) Lipid synthesis and detoxification
c) ATP production
d) Photosynthesis

11. Golgi apparatus is involved in:
a) Protein synthesis
b) Protein modification and packaging
c) DNA replication
d) ATP generation

12. Which organelle contains hydrolytic enzymes?
a) Peroxisome
b) Lysosome
c) Ribosome
d) Vacuole

13. Peroxisomes detoxify using:
a) Catalase
b) Amylase
c) Pepsin
d) Lipase

14. What is the function of the cytoskeleton?
a) Energy production
b) Structural support and movement
c) Genetic control
d) Protein packaging

15. Microtubules are composed of:
a) Actin
b) Intermediate filaments
c) Tubulin
d) Keratin

16. Flagella are made of:
a) Cilia
b) Microfilaments
c) Microtubules
d) Intermediate filaments

17. Cell membrane is primarily made of:
a) Protein
b) Phospholipid bilayer
c) Carbohydrates
d) Nucleic acids

18. Cholesterol in the plasma membrane:
a) Maintains fluidity
b) Aids in protein synthesis
c) Forms cell wall
d) Transports ions

19. Which structure is found only in plant cells?
a) Lysosome
b) Centrosome
c) Cell wall and chloroplasts
d) Centrioles

20. What is the main carbohydrate in plant cell walls?
a) Glycogen
b) Chitin
c) Cellulose
d) Starch

21. Plasmodesmata are:
a) Animal cell junctions
b) Lysosomal channels
c) Plant cell communication channels
d) Endoplasmic reticulum openings

22. Where is DNA located in prokaryotes?
a) Nucleus
b) Mitochondria
c) Nucleoid region
d) ER

23. Which structure is NOT found in prokaryotes?
a) Cell membrane
b) Ribosome
c) Mitochondria
d) Nucleoid

24. Bacterial cell walls are made of:
a) Cellulose
b) Peptidoglycan
c) Chitin
d) Glycoprotein

25. Ribosomes in prokaryotes are:
a) 80S
b) 70S
c) 60S
d) 90S

26. Which structure is involved in protein sorting and secretion?
a) Lysosome
b) Golgi complex
c) Mitochondria
d) Peroxisome

27. Semi-autonomous organelles include:
a) Lysosomes
b) Golgi
c) Mitochondria and chloroplasts
d) ER

28. Endosymbiotic theory explains origin of:
a) Nucleus
b) Mitochondria and chloroplasts
c) Ribosomes
d) Golgi

29. The term “fluid mosaic model” refers to the:
a) Cytoplasm
b) Plasma membrane
c) Cell wall
d) Nucleoid

30. Which molecules serve as cell surface markers?
a) Lipids only
b) Glycoproteins and glycolipids
c) DNA
d) Proteins only

31. In facilitated diffusion, molecules move:
a) Against gradient
b) Along concentration gradient via carrier proteins
c) With ATP
d) Only water

32. Osmosis is passage of:
a) Ions only
b) Glucose only
c) Water across a semipermeable membrane
d) Lipids

33. Active transport requires:
a) Concentration gradient
b) ATP and carrier proteins
c) Only passive diffusion
d) None

34. Exocytosis is used to:
a) Entry of molecules into cell
b) Secrete materials out of cell
c) Pump ions
d) Pinocytosis

35. Endocytosis includes:
a) Exocytosis
b) Phagocytosis and pinocytosis
c) Active transport
d) Passive diffusion

36. Cells with no nucleus are:
a) Eukaryotic
b) Prokaryotic
c) Animal
d) Plant

37. Ribosomes are made of:
a) DNA and protein
b) rRNA and protein
c) mRNA
d) Lipids

38. The nucleolus is the site of:
a) DNA replication
b) rRNA synthesis and ribosome assembly
c) Protein synthesis
d) Lipid synthesis

39. Tight junctions in animal cells:
a) Allow molecule passage
b) Prevent leakage between cells
c) Connect cytoskeletons
d) Degrade proteins

40. Desmosomes function to:
a) Transport ions
b) Provide strong adhesion between cells
c) Create water-tight barrier
d) Signal apoptosis

41. Gap junctions allow:
a) Adhesion only
b) Direct cytoplasmic connection between cells
c) DNA transfer
d) Protein secretion

42. Plants store food in:
a) Lysosomes
b) Amyloplasts
c) Mitochondria
d) ER

43. Microfilaments are made of:
a) Tubulin
b) Actin
c) Keratin
d) Collagen

44. Centrioles are found in:
a) Plant cells
b) Animal cells
c) Bacteria
d) Fungi

45. Cilia and flagella have:
a) 9+2 actin
b) 9 doublet + 2 actin
c) 9+2 microtubule arrangement
d) Intermediate filaments

46. Centrosomes are:
a) ER regions
b) Microtubule organizing centers
c) Chromatin areas
d) Ribosome clusters

47. Which ion pump helps maintain membrane potential?
a) Proton pump
b) Calcium pump
c) Sodium–potassium pump
d) Glucose transporter

48. Which dye stains acidic cell components?
a) Hematoxylin
b) Bromophenol blue
c) Acidic dye stains basic components (e.g., hematoxylin binds DNA)
d) Eosin

49. Autophagy involves:
a) Cell growth
b) Self-degradation of cell parts
c) Protein synthesis
d) ATP generation

50. Which structure is involved in cell movement?
a) Lysosome
b) Cytoskeleton
c) Golgi
d) Nucleus

51. Smooth ER helps detoxify:
a) Proteins
b) Drugs and toxins
c) Glucose
d) DNA

52. Which organelle is the cell’s “powerhouse”?
a) Chloroplast
b) Nucleus
c) Mitochondria
d) Lysosome

53. Which organelle is rich in enzymes for breaking down fatty acids?
a) Lysosome
b) Peroxisome
c) Mitochondria
d) ER

54. Which organelle packages proteins into vesicles?
a) ER
b) Golgi apparatus
c) Lysosome
d) Nucleus

55. Cell membranes are permeable to:
a) Proteins
b) Ions
c) Small nonpolar molecules
d) Carbohydrates

56. Plasmolysis occurs when a plant cell is in:
a) Hypotonic solution
b) Hypertonic solution
c) Isotonic solution
d) Pure water

57. Turgor pressure is highest in:
a) Animal cells
b) Plant cells in hypotonic solution
c) Bacterial cells
d) Animal cells in hypertonic solution

58. Amoeboid movement uses:
a) Cilia
b) Flagella
c) Pseudopodia
d) Microtubules

59. Microvilli increase:
a) Movement speed
b) Surface area for absorption
c) Structural support
d) Protein synthesis

60. Which organelle stores calcium in muscle cells?
a) Mitochondria
b) Smooth ER (sarcoplasmic reticulum)
c) Lysosome
d) Peroxisome

61. Lectin-binding glycoproteins are found on:
a) Nucleus
b) Lysosome
c) Cell membrane
d) Mitochondria

62. The glyoxysome is found in:
a) Animals
b) Plant seeds
c) Bacteria
d) Fungi

63. What does a nucleosome consist of?
a) DNA only
b) DNA wrapped around histones
c) RNA and protein
d) Lipid–protein complex

64. Euchromatin is:
a) Inactive DNA
b) Active DNA regions
c) Mitochondrial DNA
d) Ribosomal RNA

65. Heterochromatin is:
a) Actively transcribed
b) Tightly packed, inactive DNA
c) Found in chloroplasts
d) Found in lysosomes

66. Which protein unwinds DNA during replication?
a) Ligase
b) Helicase
c) Polymerase
d) Topoisomerase

67. Centromere appears during:
a) Interphase
b) Anaphase
c) Metaphase
d) Telophase

68. Chromatids separate during:
a) Metaphase
b) Anaphase
c) Telophase
d) Prophase

69. Nucleus reappears during:
a) Prophase
b) Anaphase
c) Telophase
d) Metaphase

70. Mitochondrial DNA is:
a) Linear
b) Circular
c) Satellite
d) Telomeric

71. Which dye stains proteins?
a) Eosin
b) Sudan III
c) Coomassie Brilliant Blue
d) Iodine

72. Pyrenoids are associated with:
a) Mitochondria
b) Chloroplasts in algae
c) Nucleus
d) Golgi

73. The nuclear envelope contains:
a) Peptidoglycan
b) Cellulose
c) Nuclear pores
d) Ribosomes

74. Function of nuclear pores is to:
a) Generate ATP
b) Regulate exchange of materials
c) Digest waste
d) Store calcium

75. M-phase of cell cycle is:
a) DNA replication
b) Growth phase
c) Nuclear and cell division
d) Resting phase

76. Interphase does NOT include:
a) G1
b) S
c) M phase
d) G2

77. Centrosome replication occurs during:
a) G1
b) M
c) S phase
d) G0

78. Lysosomal storage diseases result from:
a) Excess ribosomes
b) Deficiency of hydrolytic enzymes
c) Overactive mitochondria
d) Golgi malfunction

79. The nucleolus disappears during:
a) S phase
b) Prophase
c) Anaphase
d) Interphase

80. Nuclear lamina is made of:
a) Microtubules
b) Intermediate filaments
c) Actin filaments
d) Keratin

81. Which cell organelle lacks DNA?
a) Mitochondria
b) Golgi apparatus
c) Chloroplast
d) Nucleus

82. Mitophagy is:
a) Cell death
b) Degradation of mitochondria
c) Protein synthesis
d) DNA repair

83. Which structure helps segregate chromosomes?
a) Lysosome
b) Spindle fibers
c) Nucleolus
d) ER

84. The cell cycle is regulated by:
a) Lipids
b) Cyclins and CDKs
c) DNA only
d) Carbohydrates

85. G0 phase is:
a) DNA synthesis
b) Resting/non-dividing state
c) Mitosis
d) Apoptosis

86. Cell death by programmed mechanism is:
a) Necrosis
b) Apoptosis
c) Autophagy
d) Phagocytosis

87. Which cell junction seals epithelial cells?
a) Tight junction
b) Desmosome
c) Gap junction
d) Plasmodesmata

88. Which feature is common to prokaryotes and eukaryotes?
a) Nucleus
b) Membrane-bound organelles
c) Ribosomes
d) Mitochondria

89. Lipid rafts are:
a) DNA clusters
b) Microdomains in membrane rich in cholesterol
c) Protein chains
d) Ribosome aggregates

90. Which organelle is involved in lipid metabolism?
a) Golgi
b) Smooth ER
c) Lysosome
d) Nucleolus

91. Role of endosomes is to:
a) Energy production
b) Sort endocytosed materials
c) Protein synthesis
d) Photosynthesis

92. COPI and COPII vesicles are associated with:
a) Mitochondria
b) ER–Golgi transport
c) Plasma membrane
d) Lysosome

93. Which structure synthesizes lipids and steroids?
a) Rough ER
b) Smooth ER
c) Golgi
d) Lysosome

94. Protein folding occurs in:
a) Cytosol
b) Rough ER lumen
c) Nucleus
d) Mitochondria

95. The signal peptide directs proteins to:
a) Mitochondria
b) ER
c) Nucleus
d) Lysosome

96. What maintains cell shape in animal cells?
a) Cell wall
b) Cytoskeleton
c) Peroxisome
d) ER

97. Which cell type has higher surface-to-volume ratio?
a) Large cells
b) Small cells
c) Spherical cells only
d) Long cells only

98. Which organelle plays a role in cell signaling?
a) Mitochondria
b) Plasma membrane
c) Ribosome
d) Peroxisome

99. Which organelle is involved in steroid hormone synthesis?
a) Rough ER
b) Smooth ER
c) Mitochondria
d) Golgi

100. Which subcellular fraction is richest in mitochondria?
a) Nuclear pellet
b) Mitochondrial pellet
c) Microsomes
d) Cytosolic fraction