Class 9th Science Fundamental Unit of Life Practice Questions

Section A – Multiple Choice Questions (MCQs) [Q.1–20]

1. Who discovered the cell?
   a) Robert Hooke
   b) Schleiden
   c) Schwann
   d) Virchow
2. Which instrument is used to observe cells?
   a) Telescope
   b) Microscope
   c) Periscope
   d) Binoculars
3. Prokaryotic cells lack:
   a) Cell wall
   b) Nucleus with nuclear membrane
   c) Cytoplasm
   d) Ribosomes
4. The structural and functional unit of life is:
   a) Tissue
   b) Organ
   c) Cell
   d) Organ system
5. Which of the following is present only in plant cells?
   a) Cell membrane
   b) Nucleus
   c) Cell wall
   d) Mitochondria
6. Mitochondria are called:
   a) Kitchen of the cell
   b) Powerhouse of the cell
   c) Brain of the cell
   d) Packaging unit of the cell
7. Which organelle is called the “brain of the cell”?
   a) Nucleus
   b) Mitochondria
   c) Chloroplast
   d) Ribosome
8. Ribosomes are sites of:
   a) Photosynthesis
   b) Protein synthesis
   c) Respiration
   d) Secretion
9. Which figure represents the plant cell?
   (Fig: Plant cell with cell wall, chloroplasts, vacuole)
10. Which figure represents the animal cell?
    (Fig: Animal cell without cell wall, no chloroplasts)
11. The fluid inside the nucleus is called:
    a) Cytoplasm
    b) Nucleoplasm
    c) Protoplasm
    d) Vacuole
12. The term ‘cell’ was first used by:
    a) Leeuwenhoek
    b) Robert Hooke
    c) Schleiden
    d) Schwann
13. The cell organelle responsible for photosynthesis:
    a) Ribosome
    b) Mitochondria
    c) Chloroplast
    d) Lysosome
14. Which is called the “suicidal bag of the cell”?
    a) Ribosome
    b) Lysosome
    c) Nucleus
    d) Golgi apparatus
15. The plasma membrane is:
    a) Selectively permeable
    b) Freely permeable
    c) Impermeable
    d) None of these
16. The process of intake of food by unicellular organisms is called:
    a) Diffusion
    b) Endocytosis
    c) Exocytosis
    d) Osmosis
17. Plant cells maintain turgidity due to:
    a) Chloroplasts
    b) Vacuole
    c) Lysosome
    d) Nucleus
18. The cell theory was proposed by:
    a) Robert Brown
    b) Schleiden and Schwann
    c) Virchow
    d) Hooke
19. Which organelle is involved in packaging and secretion?
    a) Golgi apparatus
    b) Lysosome
    c) Ribosome
    d) Mitochondria
20. The basic difference between prokaryotic and eukaryotic cell is:
    a) Cell wall
    b) Membrane-bound organelles
    c) Ribosomes
    d) Cytoplasm

Section B – True/False [Q.21–30]

21. Plant cells contain chloroplasts.
22. Nucleus controls cell activities.
23. Plasma membrane is freely permeable.
24. Animal cells have large vacuoles.
25. Ribosomes are protein factories.
26. Cell wall is absent in plant cells.
27. Mitochondria produce energy.
28. Cytoplasm is present inside the nucleus.
29. Lysosomes help in cell digestion.
30. Endoplasmic reticulum is of two types – smooth and rough.

Section C – Fill in the Blanks [Q.31–40]

31. The __________ is called the structural and functional unit of life.
32. __________ discovered the cell in 1665.
33. The fluid present inside the cell is __________.
34. __________ are known as protein factories.
35. The double membrane organelle responsible for energy production is __________.
36. The largest cell organelle is __________.
37. __________ proposed that all cells arise from pre-existing cells.
38. The organelle responsible for photosynthesis is __________.
39. In plant cells, __________ gives rigidity and strength.
40. __________ controls all activities of the cell.

Section D – Assertion & Reason [Q.41–50]

41. Assertion: Mitochondria are called the powerhouse of the cell.
    Reason: They generate energy in the form of ATP.
42. Assertion: Cell wall is present in plant cells.
    Reason: Cell wall provides rigidity.
43. Assertion: Ribosomes are found in both prokaryotes and eukaryotes.
    Reason: They are sites of protein synthesis.
44. Assertion: Plasma membrane is selectively permeable.
    Reason: It allows only selective substances to pass through.
45. Assertion: Animal cells have chloroplasts.
    Reason: Photosynthesis occurs in animal cells.
46. Assertion: Golgi apparatus is involved in packaging.
    Reason: It helps in modification and transport of proteins.
47. Assertion: Lysosomes are called suicidal bags.
    Reason: They contain digestive enzymes.
48. Assertion: Nucleus is absent in prokaryotic cells.
    Reason: Genetic material is not enclosed by nuclear membrane.
49. Assertion: Plant cells contain large central vacuoles.
    Reason: Vacuoles help maintain turgidity.
50. Assertion: Endoplasmic reticulum is of two types.
    Reason: RER has ribosomes attached, SER does not.

Section E – Very Short Answer (1 Mark Each) [Q.51–60]

51. Who is the father of cytology?
52. Define protoplasm.
53. Name one cell organelle present in plant cell but absent in animal cell.
54. Give the function of ribosomes.
55. What is cytoplasm?
56. Which cell organelle is called the brain of the cell?
57. Define diffusion.
58. Name the energy currency of the cell.
59. Give one example of a unicellular organism.
60. What is plasmolysis?

Section F – Short Answer (2 Marks Each) [Q.61–70]

61. Draw a labeled diagram of a plant cell.
62. Draw a labeled diagram of an animal cell.
63. State two functions of mitochondria.
64. What are plastids? Name its types.
65. Differentiate between prokaryotic and eukaryotic cells.
66. Define osmosis with an example.
67. What is endocytosis?
68. State two functions of nucleus.
69. Write two differences between plant cell and animal cell.
70. Why is plasma membrane called selectively permeable?

Section G – Short Answer (3 Marks Each) [Q.71–80]

71. Explain the structure and function of Golgi apparatus.
72. Describe the role of lysosomes in cell digestion.
73. Explain the structure of mitochondria with diagram.
74. Differentiate between rough ER and smooth ER.
75. Explain the cell theory.
76. State three differences between prokaryotic and eukaryotic cells.
77. Explain the role of vacuoles in plant cells.
78. Draw a labeled diagram of nucleus.
79. Describe structure of chloroplast with diagram.
80. State differences between plant and animal cells with figures.

Section H – Long Answer (4–5 Marks Each) [Q.81–90]

81. Explain structure and functions of mitochondria with diagram.
82. Describe the structure of nucleus with labeled diagram.
83. Explain differences between prokaryotic and eukaryotic cells with examples.
84. Describe the process of plasmolysis with the help of a diagram.
85. Explain the fluid mosaic model of plasma membrane.
86. Discuss functions of endoplasmic reticulum.
87. Write the role of plastids in plants.
88. Draw labeled diagrams of plant and animal cells and compare them.
89. Explain the discovery of cell theory with contributions of scientists.
90. Describe the functions of cell organelles (any five).

Section I – Case Study Based [Q.91–100]

Case Study 1 (Q.91–95):
A student prepared slides of onion peel cells and observed them under the microscope. The cells showed cell wall, cytoplasm, nucleus, and large vacuoles.

91. Name the type of cell observed.
92. Which structure provides rigidity to these cells?
93. Why was a large vacuole observed?
94. Which cell organelle was absent in this observation?
95. Draw a simple diagram of onion peel cell.

Case Study 2 (Q.96–100):
A student prepared a slide of cheek cells. These cells showed plasma membrane, cytoplasm, and nucleus but lacked cell wall and chloroplast.

96. Name the type of cell observed.
97. Why was cell wall absent?
98. Which organelle controls cell functions here?
99. Which green organelle was absent in cheek cell?
100. Draw a labeled diagram of a cheek cell.