Practice 50+ topic-wise MCQs on Class 9 Science Chapter 2 with detailed answers. Questions cover cell theory, prokaryotic and eukaryotic cells, cell organelles (mitochondria, ribosomes, Golgi apparatus, lysosomes, chloroplasts), osmosis and diffusion, and cell division. Ideal for CBSE board exam preparation and quick revision. Aligned with NCERT syllabus 2026–27.
Class 9 Biology Chapter 2 | 50+ MCQs with Detailed Answers | Reading Time: 12 minutes
Test your understanding of the Cell chapter with these carefully curated multiple choice questions. Each question includes a detailed explanation to help you learn the concepts thoroughly. Click "Show Answer" to reveal the correct answer and explanation.
Q1. Who discovered the cell while examining a thin slice of cork under a microscope?
A) Anton van Leeuwenhoek
B) Robert Hooke
C) Robert Brown
D) Matthias Schleiden
Answer: B) Robert Hooke
Robert Hooke discovered cells in 1665 while observing cork under a primitive microscope. He coined the term "cell" because the compartments reminded him of small rooms. Learn more about cell discovery and theory.
Q2. Which scientist first observed living cells in pond water?
A) Robert Hooke
B) Robert Brown
C) Anton van Leeuwenhoek
D) Rudolf Virchow
Answer: C) Anton van Leeuwenhoek
Leeuwenhoek (1674) was the first to observe living cells under an improved microscope. He discovered bacteria, protozoa, and other microorganisms in pond water. Robert Hooke only saw dead cork cells.
Q3. According to cell theory, which statement is correct?
A) Only plants are made of cells
B) All cells arise from pre-existing cells
C) Cells are not the basic unit of life
D) All cells have a cell wall
Answer: B) All cells arise from pre-existing cells
This is the third postulate of cell theory, proposed by Rudolf Virchow (1855). It states "Omnis cellula e cellula" — every cell originates from a pre-existing cell through cell division.
Q4. The term "protoplasm" for the living substance inside the cell was coined by:
A) Robert Hooke
B) Purkinje
C) Robert Brown
D) Virchow
Answer: B) Purkinje
J.E. Purkinje (1839) coined the term "protoplasm" to describe the living fluid substance of the cell. It includes cytoplasm and nucleus.
Q5. Who discovered the nucleus in plant cells?
A) Robert Hooke
B) Robert Brown
C) Schleiden
D) Schwann
Answer: B) Robert Brown
Robert Brown (1831) discovered the nucleus in orchid cells. He recognized it as a regular feature of plant cells. The nucleus is the control center of the cell.
Q6. Cell theory does NOT apply to:
A) Plants
B) Animals
C) Viruses
D) Fungi
Answer: C) Viruses
Viruses are not made of cells and cannot reproduce on their own. They are considered on the boundary between living and non-living. Cell theory applies to all cellular organisms — plants, animals, fungi, and bacteria.
Q7. The best light microscopes can magnify objects up to approximately:
A) 100 times
B) 500 times
C) 1,500 times
D) 15,000 times
Answer: C) 1,500 times
Light (compound) microscopes can magnify objects up to about 1,400-1,500 times their actual size. For higher magnification, electron microscopes are used (up to 2,00,000 times magnification).
Q8. The statement "Omnis cellula e cellula" was given by:
A) Schleiden and Schwann
B) Rudolf Virchow
C) Robert Hooke
D) Leeuwenhoek
Answer: B) Rudolf Virchow
Virchow (1855) stated "Omnis cellula e cellula" (all cells from cells), explaining that new cells arise only from division of existing cells. This completed the cell theory.
Q9. Prokaryotic cells are characterized by:
A) Presence of a well-defined nucleus
B) Absence of nuclear membrane
C) Presence of membrane-bound organelles
D) Large cell size
Answer: B) Absence of nuclear membrane
Prokaryotic cells lack a nuclear membrane. Their genetic material (DNA) lies free in the cytoplasm as a nucleoid. Examples: bacteria and blue-green algae.
Q10. Which of the following is an example of a prokaryotic organism?
A) Amoeba
B) Yeast
C) Bacteria
D) Euglena
Answer: C) Bacteria
Bacteria are prokaryotes — they have no nucleus or membrane-bound organelles. Amoeba, yeast, and Euglena are all eukaryotic organisms with a well-defined nucleus.
Q11. The average size of a prokaryotic cell is:
A) 0.5 - 2.5 μm
B) 5 - 100 μm
C) 1 - 1.5 μm
D) 10 - 50 μm
Answer: C) 1 - 1.5 μm
Prokaryotic cells are much smaller than eukaryotic cells, typically 1-1.5 micrometers (μm) in diameter. Eukaryotic cells are usually 5-100 μm.
Q12. Which structure distinguishes a prokaryotic cell from a eukaryotic cell?
A) Cell membrane
B) Ribosomes
C) Nucleus
D) DNA
Answer: C) Nucleus
The main distinguishing feature is the nucleus. Eukaryotic cells have a membrane-bound nucleus, while prokaryotic cells have DNA in the cytoplasm without a membrane.
Q13. A mature plant cell is characterized by:
A) Small nucleus and small vacuole
B) Large nucleus and large vacuole
C) Small nucleus and large vacuole
D) No vacuole
Answer: C) Small nucleus and large vacuole
Mature plant cells have a large central vacuole that occupies most of the cell volume, pushing the nucleus and cytoplasm to the periphery. This vacuole stores water, nutrients, and waste products.
Q14. Animal cells are bounded by:
A) Plasma membrane only
B) Cell wall only
C) Both plasma membrane and cell wall
D) Nuclear membrane
Answer: A) Plasma membrane only
Animal cells have only a plasma membrane as their outer boundary. They lack a cell wall, which is found in plant cells, fungi, and bacteria.
Q15. Red blood cells in humans are:
A) Spindle-shaped
B) Disc-shaped without nucleus
C) Oval-shaped with nucleus
D) Rectangular
Answer: B) Disc-shaped without nucleus
Human RBCs are biconcave disc-shaped and lack a nucleus in their mature form. This increases surface area for oxygen transport and allows more hemoglobin to be packed inside.
Q16. The longest cell in the human body is:
A) Muscle cell
B) Nerve cell
C) Bone cell
D) Blood cell
Answer: B) Nerve cell
Nerve cells (neurons) are the longest cells in the human body. Some nerve cells can extend from the spinal cord to the toes, reaching over a meter in length.
Q17. Which type of cell can be made into a crystal?
A) Animal cell
B) Plant cell
C) Bacterial cell
D) Virus
Answer: D) Virus
Viruses can be crystallized because they are not truly cells but protein-coated genetic material. Regular cells cannot be crystallized as they are complex living structures.
Q18. Which organism contains genetic material but no nuclear membrane?
A) Fungi
B) Blue-green algae
C) Yeast
D) Amoeba
Answer: B) Blue-green algae
Blue-green algae (cyanobacteria) are prokaryotes. They have DNA but no nuclear envelope. Their DNA lies free in the cytoplasm as a nucleoid.
Q19. The cell membrane is primarily composed of:
A) Proteins only
B) Lipids only
C) Lipids and proteins
D) Carbohydrates and DNA
Answer: C) Lipids and proteins
The cell membrane is made of phospholipids (lipids) and proteins. Lipids form the bilayer structure, while proteins help in transport and cell recognition.
Q20. The plasma membrane is called "selectively permeable" because:
A) It allows all substances to pass through
B) It allows only certain substances to pass through
C) It blocks all substances
D) It has no pores
Answer: B) It allows only certain substances to pass through
The membrane is selectively permeable — it allows some molecules (like water, oxygen, CO₂) to pass while blocking others. This selective nature helps maintain cell homeostasis.
Q21. Plant cell walls are mainly made of:
A) Protein
B) Lipid
C) Cellulose
D) Chitin
Answer: C) Cellulose
Plant cell walls are made of cellulose, a complex carbohydrate (polysaccharide). Cellulose provides rigidity and structural support to plant cells.
Q22. Fungal cell walls are composed of:
A) Cellulose
B) Chitin
C) Peptidoglycan
D) Protein
Answer: B) Chitin
Fungal cell walls contain chitin, the same material found in insect exoskeletons. Plant cells have cellulose, while bacterial cells have peptidoglycan.
Q23. Which process occurs when raisins are placed in water?
A) Plasmolysis
B) Endosmosis
C) Exosmosis
D) Active transport
Answer: B) Endosmosis
When raisins are placed in water, water enters the cells by osmosis (endosmosis) because the cell sap has higher concentration than surrounding water. The raisins swell.
Q24. Plasmolysis in a plant cell is defined as:
A) Bursting of cell due to excess water
B) Shrinkage of cytoplasm in hypertonic solution
C) Shrinkage of nucleus
D) Swelling of cell wall
Answer: B) Shrinkage of cytoplasm in hypertonic solution
Plasmolysis occurs when a plant cell loses water in a hypertonic solution. The cytoplasm shrinks and pulls away from the cell wall. See this in Activity 2.2.
Q25. Which molecules can easily pass through the cell membrane by diffusion?
A) Glucose and proteins
B) Water and carbon dioxide
C) DNA and RNA
D) Large proteins
Answer: B) Water and carbon dioxide
Small, nonpolar molecules like O₂, CO₂, and water can pass through the membrane by diffusion. Large molecules like proteins require active transport.
Q26. The cell wall is absent in:
A) Plant cells
B) Bacterial cells
C) Animal cells
D) Fungal cells
Answer: C) Animal cells
Animal cells lack a cell wall. They have only a flexible plasma membrane. Plant, bacterial, and fungal cells all have cell walls for structural support.
Q27. Mitochondria are called the "powerhouse of the cell" because they:
A) Store energy
B) Generate ATP through respiration
C) Synthesize proteins
D) Break down waste
Answer: B) Generate ATP through respiration
Mitochondria produce ATP (energy currency) through aerobic respiration. This energy powers all cellular activities. Learn more about cell organelles.
Q28. Which organelle is responsible for protein synthesis?
A) Mitochondria
B) Ribosomes
C) Lysosomes
D) Vacuoles
Answer: B) Ribosomes
Ribosomes are the sites of protein synthesis. They translate mRNA into proteins. Ribosomes can be free in cytoplasm or attached to endoplasmic reticulum.
Q29. Lysosomes are known as "suicide bags" because they contain:
A) Proteins
B) Hydrolytic enzymes
C) DNA
D) Lipids
Answer: B) Hydrolytic enzymes
Lysosomes contain powerful digestive enzymes that break down waste materials and worn-out organelles. If the membrane ruptures, these enzymes can digest the cell itself.
Q30. The Golgi apparatus is primarily involved in:
A) Energy production
B) Protein modification and packaging
C) DNA replication
D) Photosynthesis
Answer: B) Protein modification and packaging
The Golgi apparatus (Golgi complex) modifies, packages, and sorts proteins and lipids for secretion or delivery to other organelles. It's the cell's "packaging and distribution center."
Q31. Which organelle is found only in plant cells?
A) Mitochondria
B) Ribosomes
C) Chloroplasts
D) Lysosomes
Answer: C) Chloroplasts
Chloroplasts are found only in plant cells. They contain chlorophyll and perform photosynthesis — converting light energy into chemical energy (glucose). See them in Activity 2.3.
Q32. The endoplasmic reticulum without ribosomes is called:
A) Rough ER
B) Smooth ER
C) Golgi apparatus
D) Nuclear envelope
Answer: B) Smooth ER
Smooth endoplasmic reticulum (SER) lacks ribosomes and is involved in lipid synthesis and detoxification. Rough ER (RER) has ribosomes and is involved in protein synthesis.
Q33. Vacuoles in plant cells function to:
A) Synthesize proteins
B) Store water, nutrients, and waste
C) Produce energy
D) Divide the cell
Answer: B) Store water, nutrients, and waste
Plant cell vacuoles store water (maintains turgor pressure), dissolved nutrients, and waste products. They also help maintain cell rigidity and can occupy up to 90% of cell volume.
Q34. Which organelle contains its own DNA and ribosomes?
A) Golgi apparatus
B) Endoplasmic reticulum
C) Mitochondria
D) Lysosomes
Answer: C) Mitochondria
Mitochondria (and chloroplasts) have their own DNA and ribosomes. This suggests they were once independent organisms that became part of eukaryotic cells (endosymbiotic theory).
Q35. Plastids that store starch are called:
A) Chloroplasts
B) Chromoplasts
C) Leucoplasts
D) Amyloplasts
Answer: D) Amyloplasts
Amyloplasts (a type of leucoplast) store starch. Chloroplasts are green (photosynthesis), chromoplasts provide color to flowers/fruits, and leucoplasts are colorless storage plastids.
Q36. The membrane surrounding a vacuole is called:
A) Tonoplast
B) Plasma membrane
C) Nuclear membrane
D) Cell wall
Answer: A) Tonoplast
The membrane surrounding the vacuole is called the tonoplast. It controls the movement of substances in and out of the vacuole, maintaining proper osmotic concentration.
Q37. Chromoplasts provide color to:
A) Leaves
B) Roots
C) Flowers and fruits
D) Stems
Answer: C) Flowers and fruits
Chromoplasts contain pigments (carotenoids) that give red, yellow, or orange color to flowers and fruits. This attracts pollinators and seed dispersers.
Q38. Which organelle helps in the formation of lysosomes?
A) Ribosomes
B) Golgi apparatus
C) Mitochondria
D) Nucleus
Answer: B) Golgi apparatus
The Golgi apparatus packages digestive enzymes into membrane-bound vesicles, forming lysosomes. These lysosomes then break down cellular waste and foreign materials.
Q39. Mitosis results in the formation of:
A) Four haploid daughter cells
B) Two identical diploid daughter cells
C) Two haploid gametes
D) One large cell
Answer: B) Two identical diploid daughter cells
Mitosis produces two daughter cells that are genetically identical to the parent cell, with the same chromosome number. It's used for growth and repair.
Q40. Meiosis occurs in:
A) Somatic cells for growth
B) Reproductive cells to form gametes
C) Root tip cells
D) Leaf cells
Answer: B) Reproductive cells to form gametes
Meiosis occurs only in reproductive organs (ovaries, testes, anthers, ovules) to produce gametes (egg and sperm) with half the chromosome number.
Q41. The chromosome number is halved during:
A) Mitosis
B) Meiosis
C) Both mitosis and meiosis
D) Binary fission
Answer: B) Meiosis
During meiosis, the chromosome number is reduced by half. For example, human cells have 46 chromosomes, but gametes have 23 chromosomes (haploid).
Q42. The term "mitosis" was coined by:
A) Flemming
B) Virchow
C) Robert Hooke
D) Schwann
Answer: A) Flemming
Walther Flemming coined the term "mitosis" in 1882 while studying cell division. He observed chromosomes (which he called "threads") dividing during cell division.
Q43. In which phase of mitosis do chromosomes align at the cell's equator?
A) Prophase
B) Metaphase
C) Anaphase
D) Telophase
Answer: B) Metaphase
During metaphase, chromosomes line up at the cell's equatorial plate (metaphase plate). Spindle fibers attach to centromeres. See this in Activity 2.5.
Q44. Chromosomes are made up of:
A) DNA only
B) Protein only
C) DNA and protein
D) RNA only
Answer: C) DNA and protein
Chromosomes consist of DNA wrapped around histone proteins. This DNA-protein complex is called chromatin. During cell division, chromatin condenses to form visible chromosomes.
Q45. Diploid somatic cells divide by:
A) Meiosis only
B) Mitosis only
C) Both mitosis and meiosis
D) Binary fission
Answer: B) Mitosis only
Somatic (body) cells divide by mitosis to produce identical diploid cells for growth and repair. Only reproductive cells undergo meiosis.
Q46. What is the correct sequence of mitosis stages?
A) Prophase → Anaphase → Metaphase → Telophase
B) Prophase → Metaphase → Anaphase → Telophase
C) Metaphase → Prophase → Anaphase → Telophase
D) Anaphase → Metaphase → Prophase → Telophase
Answer: B) Prophase → Metaphase → Anaphase → Telophase
The correct order of mitosis stages is: Prophase (chromosomes condense) → Metaphase (chromosomes align) → Anaphase (chromatids separate) → Telophase (nuclei reform).
Q47. Meiosis produces:
A) Two diploid cells
B) Four haploid cells
C) One diploid cell
D) Two haploid cells
Answer: B) Four haploid cells
Meiosis involves two divisions (Meiosis I and II), producing four daughter cells, each with half the chromosome number (haploid) of the parent cell.
Q48. Cancer is caused by:
A) Controlled cell division
B) Uncontrolled cell division
C) Lack of oxygen
D) Cell aging
Answer: B) Uncontrolled cell division
Cancer results from uncontrolled, abnormal cell division. Normal cell cycle checkpoints fail, allowing cells to divide rapidly and form tumors. This is caused by mutations in genes that control cell division.
Q49. Where does cell division occur most actively in plants?
A) Mature leaves
B) Root and shoot tips
C) Stem cortex
D) Mature fruits
Answer: B) Root and shoot tips
Cell division is most active in meristematic regions at root and shoot tips. These are growth zones where cells continuously divide by mitosis. See Activity 2.5.
Q50. The main difference between mitosis and meiosis is:
A) Mitosis is faster than meiosis
B) Mitosis maintains chromosome number; meiosis halves it
C) Meiosis occurs in all cells
D) Mitosis produces gametes
Count your correct answers and check your performance: