Chapter 8: Cell: The unit of life (NEET NOTES)
Scientist(s) Year Contribution/Discovery
Observed cork cells; coined the term cell; published observations in
Robert Hooke 1665
Micrographia (1665).
Antony von
Used simple lenses; first to observe living unicellular organisms
Leeuwenhoek 1674
(animalcules).
Corti 1772 First observed living substance in cells
Felix Dujardin 1836 Observed protoplasm in amoebae; called it Sarcode
J.E. Purkinje 1839 Coined the term Protoplasm for living substance
Robert Brown 1828 Described Brownian movement of cell particles
Robert Brown 1831 Discovered nucleus in plant cells
Schleiden & Schwann 1838-39 Proposed Cell Theory: cells are basic structural units of life
Schwann 1839 Coined the term metabolism, called cells “unit of life”
Rudolf Virchow 1858 Proposed Omnis cellula e cellula – cells arise from pre-existing cells
Fontana, Schleiden, 1781–
Observed and named nucleolus
Bowman 1840
Pringsheim & Sachs 1865–92 Described colored bodies in cytoplasm (plastids)
Haeckel 1866 Coined the term plastid
Schimper, Meyer, Errera 1883 Classified plastids: leucoplasts, chloroplasts, chromoplasts
Kollicker, Flemming 1880–82 Observed mitochondria as thread-like structures (called 'fila')
Altmann, Benda 1890–97 Described bioplasts; Benda coined term mitochondria
Camillo Golgi 1898 Discovered Golgi apparatus (internal reticular apparatus)
Fischer – Proposed Colloidal theory (best accepted theory of protoplasm nature)
Hyman – Proposed Sol-Gel theory of protoplasm
Topic 1: Cell Theory & Overview
1. Who proposed the cell theory?
a) Robert Hooke b) Schleiden & Schwann
c) Louis Pasteur d) Anton van Leeuwenhoek
2. The statement "Omnis cellula-e-cellula" was given by:
a) Rudolf Virchow b) Robert Brown
c) Matthias Schleiden d) Theodor Schwann
3. Which of the following is NOT a postulate of the cell theory?
a) All living organisms are composed of cells.
b) Cells arise from pre-existing cells.
c) Cells are the smallest living units.
d) All cells have a nucleus.
4. The first living cell observed under a microscope was discovered by:
a) Robert Hooke b) Anton van Leeuwenhoek
c) Schleiden d) Schwann
5. Which microscope is used to study detailed structure of cell organelles?
a) Light microscope b) Electron microscope
c) Compound microscope d) Dissecting microscope
Topic 2: Prokaryotic & Eukaryotic Cells
6. Prokaryotic cells lack:
a) Cell membrane b) Ribosomes
c) Nuclear membrane d) Cytoplasm
7. The genetic material in prokaryotes is:
a) Enclosed in a nucleus b) Circular and naked DNA
c) Linear DNA with histones d) Absent
8. Mesosomes in prokaryotes are:
a) Storage granules b) Infoldings of the plasma membrane
c) Gas vesicles d) Ribosomal subunits
9. Which structure is present in both prokaryotes and eukaryotes?
a) Mitochondria b) Ribosomes
c) Endoplasmic reticulum d) Golgi apparatus
10.The cell wall of prokaryotes is made up of:
a) Cellulose b) Peptidoglycan
c) Chitin d) Phospholipids
Topic 3: Cell Organelles & Functions
11.The powerhouse of the cell is:
a) Nucleus b) Mitochondria
c) Chloroplast d) Golgi body
12.Ribosomes are the site of:
a) Lipid synthesis b) Protein synthesis
c) DNA replication d) Photosynthesis
13.Which organelle contains digestive enzymes?
a) Peroxisome b) Lysosome
c) Glyoxysome d) Ribosome
14.The function of the Golgi apparatus is:
a) Protein synthesis b) Packaging & secretion
c) Cellular respiration d) DNA replication
15.Smooth ER is involved in:
a) Protein synthesis b) Lipid synthesis
c) ATP production d) Waste elimination
Topic 4: Nucleus & Chromosomes
16.The dense, spherical structure inside the nucleus is:
a) Nucleolus b) Chromatin
c) Centrosome d) Ribosome
17.Chromatin is composed of:
a) DNA + RNA b) DNA + Histones
c) RNA + Proteins d) Lipids + Proteins
18.Nuclear pores allow the transport of:
a) Only DNA b) Only proteins
c) RNA and proteins d) Only water
19.The number of chromosomes in humans is:
a) 23 b) 46 c) 22 d) 44
20.The thread-like structures in the nucleus during interphase are:
a) Chromosomes b) Chromatin
c) Centrioles d) Microtubules
Topic 5: Cell Membrane & Cell Wall
21.The fluid mosaic model describes the structure of:
a) Cell wall b) Plasma membrane
c) Nucleus d) Mitochondria
22.The main component of the plasma membrane is:
a) Cellulose b) Phospholipids
c) Proteins d) Nucleic acids
23.Which is NOT a function of the plasma membrane?
a) Transport b) Cell recognition
c) Protein synthesis d) Signal transduction
24.The cell wall of plants is made of:
a) Chitin b) Cellulose
c) Peptidoglycan d) Lipids
25.Which of the following is absent in animal cells?
a) Cell membrane b) Centrioles
c) Cell wall d) Mitochondria
Answers:
1. b) Schleiden & Schwann, 2. a) Rudolf Virchow, 3. d) All cells have a nucleus, 4. b)
Anton van Leeuwenhoek, 5. b) Electron microscope, 6. c) Nuclear membrane, 7. b)
Circular and naked DNA, 8. b) Infoldings of the plasma membrane, 9. b) Ribosomes, 10.
b) Peptidoglycan, 11. b) Mitochondria, 12. b) Protein synthesis, 13. b) Lysosome, 14. b)
Packaging & secretion, 15. b) Lipid synthesis, 16. a) Nucleolus, 17. b) DNA + Histones,
18. c) RNA and proteins, 19. b) 46, 20. b) Chromatin, 21. b) Plasma membrane, 22. b)
Phospholipids, 23. c) Protein synthesis, 24. b) Cellulose, 25. c) Cell wall.
1. Prokaryotic Cell Structure
1. Which of the following is present in a prokaryotic cell? (NEET 2022)
a) Mitochondria b) Endoplasmic reticulum
c) Mesosome d) Nuclear envelope
2. The structure formed by the extension of the plasma membrane in prokaryotes
for respiration is: (NEET 2021)
a) Glyoxysome b) Mesosome
c) Peroxisome d) Spherosome
3. Which of the following is absent in prokaryotes? (NEET 2020)
a) Ribosomes b) DNA c) Plasma membrane d) Histones
4. The cell wall of prokaryotes is composed of: (NEET 2019)
a) Cellulose b) Chitin c) Peptidoglycan d) Hemicellulose
5. Plasmids in bacteria are: (NEET 2018)
a) Circular DNA molecules b) Required for survival
c) Part of the chromosome d) Always linear
2. Eukaryotic Cell Organelles
6. Which organelle is called the "suicidal bag" of the cell? (NEET 2022)
a) Peroxisome b) Lysosome c) Ribosome d) Glyoxysome
7. The function of the rough endoplasmic reticulum (RER) is: (NEET 2021)
a) Lipid synthesis b) Protein synthesis
c) Detoxification d) ATP synthesis
8. Which organelle is responsible for the synthesis of steroidal hormones? (NEET
2020)
a) Golgi apparatus b) Smooth ER
c) Rough ER d) Lysosome
9. The Golgi apparatus is involved in: (NEET 2019)
a) Protein synthesis b) Formation of lysosomes
c) Cellular respiration d) DNA replication
10.Which of the following is not a double-membrane-bound organelle? (NEET 2018)
a) Nucleus b) Mitochondria
c) Chloroplast d) Lysosome
3. Nucleus & Chromosomes
11.The nuclear membrane is absent in: (NEET 2022)
a) Fungi b) Protists c) Prokaryotes d) Higher plants
12.Chromatin consists of: (NEET 2021)
a) DNA + RNA b) DNA + Histones
c) RNA + Proteins d) Lipids + Proteins
13.Nucleolus is the site for the synthesis of: (NEET 2020)
a) rRNA b) tRNA c) mRNA d) DNA
14.The number of chromosomes in a human gamete is: (NEET 2019)
a) 23 b) 46 c) 22 d) 44
15.Which of the following is not a part of the nucleus? (NEET 2018)
a) Nucleolus b) Chromatin c) Centrosome d) Nuclear pore
4. Cell Membrane & Transport
16.The fluid mosaic model of the plasma membrane was proposed by: (NEET 2022)
a) Schleiden & Schwann b) Singer & Nicolson
c) Robert Hooke d) Camillo Golgi
17.Which of the following is not a function of the plasma membrane? (NEET 2021)
a) Cell recognition b) Protein synthesis
c) Selective permeability d) Signal transduction
18.The movement of water across a semi-permeable membrane is called: (NEET
2020)
a) Diffusion b) Osmosis c) Active transport d) Facilitated diffusion
19.Which of the following is not a passive transport mechanism? (NEET 2019)
a) Osmosis b) Diffusion c) Phagocytosis d) Facilitated diffusion
20.The main lipid component of the plasma membrane is: (NEET 2018)
a) Cholesterol b) Phospholipids
c) Glycolipids d) Triglycerides
5. Specialized Cell Structures
21.Which structure helps in cell division in animal cells? (NEET 2022)
a) Centriole b) Ribosome c) Lysosome d) Peroxisome
22.The motile structure in prokaryotes is: (NEET 2021)
a) Pili b) Flagella c) Cilia d) Mesosome
23.Which of the following is present in plant cells but absent in animal cells? (NEET
2020)
a) Mitochondria b) Centrioles c) Plastids d) Ribosomes
24.The function of the contractile vacuole in protozoans is: (NEET 2019)
a) Digestion b) Osmoregulation c) Respiration d) Reproduction
25.Which of the following is not a function of the cytoskeleton? (NEET 2018)
a) Cell motility b) Cell shape maintenance
c) Protein synthesis d) Intracellular transport
Answers: 1. c) Mesosome, 2. b) Mesosome, 3. d) Histones , 4. c) Peptidoglycan, 5. a)
Circular DNA molecules, 6. b) Lysosome, 7. b) Protein synthesis, 8. b) Smooth ER, 9. b)
Formation of lysosomes, 10. d) Lysosome, 11. c) Prokaryotes, 12. b) DNA + Histones,
13. a) rRNA, 14. a) 23, 15. c) Centrosome, 16. b) Singer & Nicolson, 17. b) Protein
synthesis, 18. b) Osmosis, 19. c) Phagocytosis, 20. b) Phospholipids, 21. a) Centriole, 22.
b) Flagella, 23. c) Plastids, 24. b) Osmoregulation, 25. c) Protein synthesis.
I. Assertion-Reasoning Questions
Directions: Each question contains an Assertion (A) and a Reason (R). Choose the
correct option:
a) Both A and R are true, and R explains A.
b) Both A and R are true, but R does not explain A.
c) A is true, but R is false.
d) A is false, but R is true.
1. Assertion (A): Prokaryotic cells lack a true nucleus.
Reason (R): They do not have a nuclear membrane or membrane-bound organelles.
2. Assertion (A): Lysosomes are called "suicidal bags" of the cell.
Reason (R): They contain oxidizing enzymes that digest cellular waste and dead
organelles.
3. Assertion (A): The fluid mosaic model explains the structure of the protoplasm
Reason (R): It consists of a phospholipid bilayer with embedded proteins in a fluid
arrangement.
4. Assertion (A): Mitochondria are semi-autonomous organelles.
Reason (R): They contain their own DNA and ribosomes for protein synthesis.
5. Assertion (A): Plant cells do not burst in hypotonic solutions.
Reason (R): Their cell wall provides rigidity and prevents lysis.
II. Case Study-Based Questions
Case Study 1: A scientist observed a cell under an electron microscope and noted the
following features:
No nuclear membrane
Presence of 70S ribosomes
Cell wall made of peptidoglycan
6. The observed cell is most likely a:
a) Eukaryotic plant cell b) Prokaryotic bacterial cell
c) Fungal cell d) Animal cell
7. Which additional structure might be present in this cell?
a) Golgi apparatus b) Mesosome
c) Chloroplast d) Endoplasmic reticulum
Case Study 2: A student conducted an experiment to study osmosis using a potato and
sugar solution.
8. If the potato strip shrinks in the solution, the solution is:
a) Hypotonic b) Isotonic c) Hypertonic d) None of these
9. The movement of water in this experiment occurs through:
a) Active transport b) Semi-permeable membrane of potato cells
c) Diffusion only d) Phagocytosis
III. Experimental-Based Questions
10.In an experiment, cells were treated with a detergent that dissolves lipids. Which
organelle would be most affected?
a) Nucleus b) Mitochondria c) Plasma membrane d) Ribosomes
11.A scientist isolates an organelle that synthesizes ATP. Which technique was most
likely used?
a) Chromatography b) Centrifugation
c) PCR d) Electrophoresis
12.When a cell is placed in a hypertonic solution, it shrinks. This process is called:
a) Plasmolysis b) Hemolysis c) Crenation d) Turgidity
13.In an experiment, ribosomes were removed from a cell. Which process would be
directly affected?
a) Lipid synthesis b) Protein synthesis c) DNA replication d) Photosynthesis
14.A cell lacking mitochondria would be unable to perform:
a) Glycolysis b) Kreb’s cycle c) Anaerobic respiration d) All of the above
Answers:
Case Study-Based:
6. b) Prokaryotic bacterial cell, 7. b) Mesosome, 8. c) Hypertonic, 9. b) Semi-
permeable membrane of potato cells.
Experimental-Based:
10. c) Plasma membrane, 11. b) Centrifugation, 12. a) Plasmolysis, 13. b) Protein
synthesis, 14. b) Kreb’s cycle.
