1. The basic structural and functional unit of life is ___________.
A) Tissue
B) Cell
C) Organ
D) Organ system
Answer: B
Explanation: All living organisms are made up of cells – the fundamental unit of life.
2. The term “cell” was first coined by___________.
A) Robert Hooke
B) Schleiden
C) Schwann
D) Virchow
Answer: A
Explanation: Hooke (1665) observed cork cells under a microscope and called them “cells.”
3. The cell theory was proposed by___________.
A) Watson and Crick
B) Schleiden and Schwann
C) Darwin and Wallace
D) Virchow and Hooke
Answer: B
Explanation: Schleiden and Schwann (1838–39) proposed the cell theory.
4. Who stated “All cells arise from pre-existing cells”?
A) Schwann
B) Schleiden
C) Virchow
D) Hooke
Answer: C
Explanation: Rudolf Virchow (1855) added “Omnis cellula e cellula.”
5. Prokaryotic cells lack___________.
A) Cell wall
B) Plasma membrane
C) Nucleus with nuclear membrane
D) Cytoplasm
Answer: C
Explanation: Prokaryotes (bacteria, cyanobacteria) have no true nucleus.
6. Which of the following is a prokaryote?
A) Amoeba
B) Bacteria
C) Paramecium
D) Algae
Answer: B
Explanation: Bacteria are prokaryotic, with no membrane-bound nucleus or organelles.
7. Eukaryotic cells are characterized by the presence of___________.
A) Nucleus and membrane-bound organelles
B) Cell wall always
C) No DNA
D) Only RNA
Answer: A
Explanation: Eukaryotes have true nucleus and organelles like mitochondria, ER, Golgi.
8. Plasma membrane is mainly composed of___________.
A) Proteins only
B) Lipids only
C) Proteins and lipids
D) Proteins, lipids, and carbohydrates
Answer: D
Explanation: Plasma membrane follows the fluid mosaic model (lipid bilayer with proteins).
9. Plasma membrane allows only selective substances to pass. It is___________.
A) Permeable
B) Semi-permeable
C) Impermeable
D) Fully permeable
Answer: B
Explanation: Plasma membrane is selectively permeable.
10. Diffusion across plasma membrane occurs___________.
A) Against concentration gradient
B) Along concentration gradient
C) By using ATP
D) By endocytosis only
Answer: B
Explanation: Diffusion is passive transport.
11. The process by which a cell engulfs solid particles is called___________.
A) Pinocytosis
B) Phagocytosis
C) Exocytosis
D) Diffusion
Answer: B
Explanation: Phagocytosis = “cell eating.”
12. The process of ingestion of liquid into cell is called___________.
A) Phagocytosis
B) Pinocytosis
C) Diffusion
D) Osmosis
Answer: B
Explanation: Pinocytosis = “cell drinking.”
13. Osmosis is movement of water across membrane from___________.
A) High solute to low solute
B) Low water to high water concentration
C) High water to low water concentration
D) None
Answer: C
Explanation: Osmosis moves water down its concentration gradient.
14. Plant cells placed in hypotonic solution will___________.
A) Shrink
B) Burst
C) Become turgid
D) Plasmolyze
Answer: C
Explanation: Water enters cell → cell swells, becomes turgid.
15. Animal cells placed in hypertonic solution will___________.
A) Burst
B) Shrink (crenation)
C) Become turgid
D) No change
Answer: B
Explanation: Water moves out → cell shrinks.
16. Plasmolysis is___________.
A) Shrinking of protoplasm in hypertonic solution
B) Swelling of cell in hypotonic solution
C) Cell bursting
D) Normal condition of cell
Answer: A
Explanation: Water loss causes cell membrane to detach from wall.
17. Which organelle is called the “control center of the cell”?
A) Nucleus
B) Mitochondria
C) Ribosome
D) Golgi body
Answer: A
Explanation: Nucleus controls all activities of the cell.
18. DNA in prokaryotic cell is___________.
A) Linear and enclosed in nucleus
B) Circular and naked
C) Absent
D) Attached to mitochondria
Answer: B
Explanation: Prokaryotic DNA is circular, without histone proteins.
19. Eukaryotic DNA is___________.
A) Circular and naked
B) Linear and associated with histones
C) Absent
D) Only RNA
Answer: B
Explanation: DNA in eukaryotes is organized into chromosomes.
20. The cell wall of plants is made of___________.
A) Chitin
B) Cellulose
C) Peptidoglycan
D) Protein
Answer: B
Explanation: Plant cell wall is composed mainly of cellulose.
21. The cell wall of fungi is made of___________.
A) Cellulose
B) Chitin
C) Peptidoglycan
D) Protein
Answer: B
Explanation: Fungal cell wall is made of chitin.
22. The cell wall of bacteria is made of___________.
A) Chitin
B) Cellulose
C) Peptidoglycan
D) Starch
Answer: C
Explanation: Peptidoglycan provides rigidity in bacterial walls.
23. Animal cells lack___________.
A) Plasma membrane
B) Nucleus
C) Mitochondria
D) Cell wall
Answer: D
Explanation: Animal cells have only plasma membrane, no cell wall.
24. Plant cells usually have a large central___________.
A) Mitochondrion
B) Vacuole
C) Golgi body
D) Nucleus
Answer: B
Explanation: Vacuoles store water, nutrients, and maintain turgidity.
25. The green pigment chlorophyll is located in___________.
A) Golgi body
B) Mitochondria
C) Chloroplasts
D) Nucleus
Answer: C
Explanation: Chloroplasts contain chlorophyll for photosynthesis.
26. The double-membrane structure containing DNA in eukaryotic cells is___________.
A) Mitochondria
B) Chloroplast
C) Nucleus
D) Ribosome
Answer: C
Explanation: Nucleus is bound by a double nuclear envelope and contains DNA.
27. The liquid content of the nucleus is called___________.
A) Cytoplasm
B) Nucleoplasm
C) Matrix
D) Chromatin
Answer: B
Explanation: Nucleoplasm (nuclear sap) surrounds chromatin and nucleolus.
28. Chromatin is made of___________.
A) DNA only
B) DNA and proteins (histones)
C) RNA only
D) Protein only
Answer: B
Explanation: Chromatin = DNA wrapped around histone proteins.
29. The site of ribosome synthesis in nucleus is___________.
A) Nuclear pore
B) Chromatin
C) Nucleolus
D) Nuclear envelope
Answer: C
Explanation: Nucleolus is the center for rRNA synthesis and ribosome assembly.
30. Which organelle is called the “powerhouse of the cell”?
A) Nucleus
B) Ribosome
C) Mitochondria
D) Golgi apparatus
Answer: C
Explanation: Mitochondria generate ATP via cellular respiration.
31. Mitochondria have their own___________.
A) DNA and ribosomes
B) Only DNA
C) Only RNA
D) None
Answer: A
Explanation: Mitochondria are semi-autonomous and can synthesize some proteins.
32. The inner folds of mitochondria are called___________.
A) Thylakoids
B) Cristae
C) Grana
D) Matrix
Answer: B
Explanation: Cristae increase surface area for ATP production.
33. The fluid inside mitochondria is called___________.
A) Stroma
B) Cytoplasm
C) Matrix
D) Nucleoplasm
Answer: C
Explanation: Mitochondrial matrix contains enzymes for Krebs cycle.
34. The organelle responsible for protein synthesis is___________.
A) Golgi body
B) Lysosome
C) Ribosome
D) Vacuole
Answer: C
Explanation: Ribosomes synthesize proteins from mRNA.
35. Ribosomes are made of:
A) Proteins only
B) RNA only
C) rRNA and proteins
D) DNA and proteins
Answer: C
Explanation: Ribosomes consist of ribosomal RNA and proteins.
36. The ribosomes attached to ER form:
A) Smooth ER
B) Rough ER
C) Golgi complex
D) Plastids
Answer: B
Explanation: Rough ER is studded with ribosomes and synthesizes proteins.
37. Smooth endoplasmic reticulum is mainly involved in:
A) Protein synthesis
B) Lipid and steroid synthesis
C) ATP production
D) Cell division
Answer: B
Explanation: Smooth ER manufactures lipids and detoxifies harmful substances.
38. Rough ER is mainly involved in:
A) Lipid synthesis
B) Protein synthesis
C) ATP synthesis
D) DNA replication
Answer: B
Explanation: Ribosomes on RER make proteins for secretion and membranes.
39. The organelle that packages and modifies proteins is___________.
A) Lysosome
B) Ribosome
C) Golgi apparatus
D) Vacuole
Answer: C
Explanation: Golgi modifies, sorts, and packages proteins for transport.
40. The Golgi apparatus was discovered by___________.
A) Camillo Golgi
B) Robert Hooke
C) Schleiden
D) Schwann
Answer: A
Explanation: Italian scientist Golgi discovered it in 1898.
41. The “suicidal bags” of the cell are___________.
A) Ribosomes
B) Lysosomes
C) Vacuoles
D) Golgi bodies
Answer: B
Explanation: Lysosomes contain digestive enzymes that can destroy cell contents.
42. Lysosomes contain___________.
A) DNA
B) Digestive enzymes
C) Ribosomes
D) RNA
Answer: B
Explanation: Hydrolytic enzymes digest macromolecules.
43. Which organelle digests worn-out cell organelles?
A) Ribosome
B) Lysosome
C) Vacuole
D) Nucleus
Answer: B
Explanation: Lysosomes recycle and digest damaged organelles.
44. The network of tubules providing intracellular transport is___________.
A) Ribosome
B) ER (Endoplasmic Reticulum)
C) Golgi body
D) Lysosome
Answer: B
Explanation: ER transports proteins and lipids inside cells.
45. Ribosomes are absent in___________.
A) Rough ER
B) Cytoplasm
C) Nucleus
D) Smooth ER
Answer: D
Explanation: SER lacks ribosomes; hence it does not synthesize proteins.
46. Which organelle is abundant in liver cells for detoxification?
A) Lysosome
B) Rough ER
C) Smooth ER
D) Ribosome
Answer: C
Explanation: SER detoxifies drugs and harmful substances in liver.
47. Which cell organelle is called “protein factory”?
A) Ribosome
B) Mitochondria
C) Nucleus
D) Golgi body
Answer: A
Explanation: Ribosomes translate mRNA into proteins.
48. Proteins synthesized in RER are transported to Golgi by___________.
A) Lysosomes
B) Vesicles
C) Centrioles
D) Vacuoles
Answer: B
Explanation: Transport vesicles carry proteins from ER to Golgi.
49. Secretory vesicles of cell originate from___________.
A) Ribosomes
B) Golgi apparatus
C) Lysosomes
D) Mitochondria
Answer: B
Explanation: Golgi packages secretory products into vesicles.
50. Autolysis (self-destruction of cell) is caused by rupture of___________.
A) Ribosomes
B) Golgi body
C) Lysosomes
D) Vacuole
Answer: C
Explanation: Release of hydrolytic enzymes causes cell death (autolysis).
51. Plastids are found only in___________.
A) Animal cells
B) Plant cells
C) Bacteria
D) Fungi
Answer: B
Explanation: Plastids are double-membrane organelles present only in plants and algae.
52. The green pigment chlorophyll is located in___________.
A) Mitochondria
B) Chloroplasts
C) Golgi apparatus
D) Nucleus
Answer: B
Explanation: Chloroplasts contain chlorophyll essential for photosynthesis.
53. The double-membrane organelle with its own DNA and ribosomes in plants is___________.
A) Ribosome
B) Chloroplast
C) Lysosome
D) Vacuole
Answer: B
Explanation: Chloroplasts are semi-autonomous, containing DNA and 70S ribosomes.
54. Chromoplasts contain___________.
A) Chlorophyll
B) Carotenoids (xanthophylls and carotene)
C) Starch
D) Protein
Answer: B
Explanation: Chromoplasts give yellow, orange, and red colors to fruits and flowers.
55. Leucoplasts are specialized for storing___________.
A) Pigments
B) Starch, oils, and proteins
C) DNA
D) Hormones
Answer: B
Explanation: Leucoplasts are colorless plastids for food storage.
56. Amyloplasts store___________.
A) Oil
B) Starch
C) Protein
D) Pigments
Answer: B
Explanation: Amyloplasts are starch-storing leucoplasts.
57. Elaioplasts store___________.
A) Lipids (oils)
B) Proteins
C) Starch
D) Pigments
Answer: A
Explanation: Elaioplasts store fats and oils.
58. Aleuroplasts store___________.
A) Pigments
B) Starch
C) Proteins
D) Oils
Answer: C
Explanation: Aleuroplasts are protein-storing plastids.
59. The site of light reactions of photosynthesis is___________.
A) Mitochondria
B) Cytoplasm
C) Thylakoid membrane of chloroplast
D) Stroma of chloroplast
Answer: C
Explanation: Light reactions occur in thylakoids, producing ATP and NADPH.
60. The site of dark reaction (Calvin cycle) is___________.
A) Cristae
B) Cytoplasm
C) Stroma of chloroplast
D) Ribosome
Answer: C
Explanation: The stroma contains enzymes for the Calvin cycle.
61. The stacked structures in chloroplasts are called___________.
A) Cristae
B) Grana
C) Thylakoids
D) Stroma
Answer: B
Explanation: Grana are stacks of thylakoid discs.
62. The large central vacuole in plant cells is filled with___________.
A) Cytoplasm
B) Cell sap
C) Chromatin
D) Proteins only
Answer: B
Explanation: Vacuoles store water, ions, sugars, pigments, and waste products.
63. In animal cells, vacuoles are___________.
A) Large and central
B) Small and temporary
C) Absent
D) Pigment-filled
Answer: B
Explanation: Vacuoles are large in plants, small in animal cells.
64. Plant cell wall is mainly composed of___________.
A) Chitin
B) Cellulose
C) Glycogen
D) Protein
Answer: B
Explanation: Plant cell wall is rigid and made of cellulose fibers.
65. Middle lamella of plant cell wall is rich in___________.
A) Cellulose
B) Calcium pectate
C) Lignin
D) Protein
Answer: B
Explanation: Middle lamella cements plant cells together.
66. Which of the following is present only in plant cells, not in animal cells?
A) Plasma membrane
B) Mitochondria
C) Cell wall
D) Ribosomes
Answer: C
Explanation: Cell wall is a plant cell-specific structure.
67. Which of the following is present only in animal cells, not in plant cells?
A) Chloroplast
B) Centrioles
C) Cell wall
D) Vacuole
Answer: B
Explanation: Centrioles are present in animal cells and help in cell division.
68. The jelly-like substance between cell wall and cell membrane in plants is___________.
A) Plasmodesmata
B) Middle lamella
C) Protoplasm
D) Cytosol
Answer: B
Explanation: Middle lamella holds neighboring plant cells together.
69. In plant cells, cytoplasmic connections between cells are called___________.
A) Desmosomes
B) Plasmodesmata
C) Gap junctions
D) Tight junctions
Answer: B
Explanation: Plasmodesmata connect cytoplasm of adjacent plant cells.
70. Cellulose is absent in___________.
A) Plant cell wall
B) Algal cell wall
C) Animal cells
D) Cotton fibers
Answer: C
Explanation: Animal cells have no cell wall or cellulose.
71. Which pigment provides red, orange, and yellow color to plant parts?
A) Chlorophyll
B) Carotenoids
C) Anthocyanins
D) Phycobilins
Answer: B
Explanation: Carotenoids in chromoplasts provide bright colors.
72. Anthocyanins are pigments present in___________.
A) Chloroplast
B) Vacuole sap
C) Mitochondria
D) Nucleus
Answer: B
Explanation: Anthocyanins dissolved in vacuole give red, blue, purple color.
73. Which plant cell organelle stores waste products?
A) Lysosome
B) Nucleus
C) Vacuole
D) Golgi body
Answer: C
Explanation: Vacuole acts as a storage site for wastes and toxins.
74. Which of the following organelles is absent in mature red blood cells of mammals?
A) Ribosome
B) Nucleus
C) Mitochondria
D) All of the above
Answer: D
Explanation: Mammalian RBCs lack nucleus, ribosomes, and mitochondria for more hemoglobin space.
75. The feature present in plant cells but absent in animal cells is___________.
A) Cell wall, chloroplast, large central vacuole
B) Plasma membrane, mitochondria, ribosome
C) Centrioles, lysosomes, small vacuole
D) Golgi, ER, cytoplasm
Answer: A
Explanation: These are unique distinguishing features of plant cells.
76. The term “protoplasm” was coined by___________.
A) Robert Brown
B) J.E. Purkinje
C) Robert Hooke
D) Virchow
Answer: B
Explanation: Purkinje (1839) coined “protoplasm” for living content inside cell.
77. The first cell organelle discovered was___________.
A) Mitochondria
B) Nucleus
C) Chloroplast
D) Ribosome
Answer: B
Explanation: Robert Brown (1831) discovered the cell nucleus.
78. Which is the smallest cell in the human body?
A) RBC
B) Nerve cell
C) Sperm cell
D) Platelet
Answer: C
Explanation: Human sperm is one of the smallest cells.
79. Which is the largest human cell?
A) Liver cell
B) Ovum (egg cell)
C) Neuron
D) Muscle cell
Answer: B
Explanation: The ovum is the largest single cell in the human body.
80. Which is the longest cell in the human body?
A) RBC
B) Muscle cell
C) Nerve cell (neuron)
D) Epithelial cell
Answer: C
Explanation: Neurons can extend over a meter in length.
81. Which organelle is absent in prokaryotic cells?
A) Ribosome
B) Mitochondria
C) Plasma membrane
D) DNA
Answer: B
Explanation: Prokaryotes lack membrane-bound organelles.
82. Which organelle is known as “cell’s digestive system”?
A) Ribosome
B) Lysosome
C) ER
D) Golgi body
Answer: B
Explanation: Lysosomes digest waste and worn-out organelles.
83. Which organelle is called “cell’s post office”?
A) Nucleus
B) Golgi apparatus
C) Ribosome
D) Mitochondria
Answer: B
Explanation: Golgi sorts, modifies, and packages proteins like a postal system.
84. Semi-autonomous organelles include___________.
A) Nucleus, mitochondria, chloroplast
B) Golgi and lysosome
C) ER and vacuole
D) Ribosome and centrosome
Answer: A
Explanation: They have their own DNA and ribosomes, able to divide.
85. The endosymbiotic theory explains the origin of___________.
A) Nucleus
B) Mitochondria and chloroplasts
C) Ribosomes
D) Cell wall
Answer: B
Explanation: They originated from free-living bacteria engulfed by ancestors of eukaryotic cells.
86. The cytoskeleton of a cell is made of___________.
A) Microtubules and microfilaments
B) Mitochondria and ribosomes
C) Lysosomes and vacuoles
D) ER and Golgi
Answer: A
Explanation: Cytoskeleton provides shape, support, and intracellular transport.
87. Centrioles are absent in___________.
A) Animal cells
B) Plant cells
C) Protozoa
D) Fungi
Answer: B
Explanation: Higher plants lack centrioles, but animal cells have them.
88. Which organelle is involved in photorespiration in plants?
A) Chloroplast
B) Mitochondria
C) Peroxisome
D) Ribosome
Answer: C
Explanation: Peroxisomes participate in photorespiration and fatty acid metabolism.
89. The “ribosome” was first observed by___________.
A) George Palade
B) Robert Brown
C) Schleiden
D) Schwann
Answer: A
Explanation: Palade (1955) discovered ribosomes using electron microscopy.
90. The outermost layer of animal cell is___________.
A) Cell wall
B) Plasma membrane
C) Capsule
D) Middle lamella
Answer: B
Explanation: Animal cells lack cell wall; plasma membrane is outermost.
91. The outermost layer of plant cell is___________.
A) Plasma membrane
B) Cell wall
C) Middle lamella
D) Capsule
Answer: B
Explanation: Cell wall of cellulose provides rigidity.
92. Which organelle is called the “engine of the cell”?
A) Ribosome
B) Mitochondria
C) Golgi body
D) Nucleus
Answer: B
Explanation: Mitochondria generate ATP, the cell’s energy currency.
93. The cell junctions in plant cells are___________.
A) Desmosomes
B) Plasmodesmata
C) Gap junctions
D) Tight junctions
Answer: B
Explanation: Plasmodesmata connect cytoplasm of neighboring plant cells.
94. Cell division in animal cells starts with___________.
A) Cell plate formation
B) Cleavage furrow formation
C) Spindle disappearance
D) Nuclear fusion
Answer: B
Explanation: Animal cytokinesis occurs by furrowing of membrane.
95. Cell division in plant cells starts with___________.
A) Cleavage furrow formation
B) Cell plate formation
C) Spindle disintegration
D) Chromosome condensation
Answer: B
Explanation: Cellulose vesicles form a plate dividing plant cells.
96. In animal cells, lysosomes are formed from___________.
A) ER
B) Ribosomes
C) Golgi apparatus
D) Nucleus
Answer: C
Explanation: Golgi produces lysosomal vesicles with hydrolytic enzymes.
97. Which organelle detoxifies hydrogen peroxide?
A) Lysosome
B) Peroxisome
C) Ribosome
D) ER
Answer: B
Explanation: Peroxisomes break down H₂O₂ into water and oxygen.
98. The plant vacuole membrane is called___________.
A) Plasmalemma
B) Tonoplast
C) Cell wall
D) Endomembrane
Answer: B
Explanation: Tonoplast is a specialized membrane surrounding vacuole.
99. Which of the following is absent in mature mammalian red blood cells?
A) Plasma membrane
B) Nucleus and organelles
C) Hemoglobin
D) Cytoplasm
Answer: B
Explanation: RBCs lack nucleus and organelles to maximize oxygen-carrying hemoglobin.
100. Which structure is common to both plant and animal cells?
A) Cell wall
B) Chloroplast
C) Plasma membrane, mitochondria, ribosomes
D) Centrioles
Answer: C
Explanation: Both cell types have plasma membrane, ribosomes, mitochondria, ER, Golgi, etc.