This Class 9 Science Chapter 2 Sample Paper 4 is based on “Cell: The Building Block of Life.” It provides comprehensive chapter-wise practice through objective, conceptual, application-based, and competency-focused questions. The paper covers cell theory, cell structure, organelles, plant and animal cells, prokaryotic and eukaryotic cells, diffusion, osmosis, and cellular organisation, with complete solutions provided at the end.

Sample Paper 4

Class: 9 Subject: Science
Chapter: 2 – Cell: The Building Block of Life
Maximum Marks: 50
Suggested Time: 1 Hour 30 Minutes

General Instructions

1. All questions are compulsory.
2. Read each question carefully before answering.
3. Draw neat and labelled diagrams wherever required.
4. Use appropriate scientific terminology.
5. Show all necessary reasoning in application-based questions.

Section A — Objective Questions

10 × 1 = 10 Marks

Q1. Which scientist is associated with the discovery of cells while observing cork?

a) Robert Hooke
b) Robert Brown
c) Rudolf Virchow
d) Matthias Schleiden

Q2. Which statement is correct about cells?

a) All cells are visible to the naked eye.
b) Cells are the basic structural and functional units of living organisms.
c) Only animals are made up of cells.
d) Cells do not contain genetic material.

Q3. Which structure is present in both plant and animal cells?

a) Cell wall
b) Chloroplast
c) Plasma membrane
d) Large central vacuole

Q4. Which organelle contains the genetic material in a typical eukaryotic cell?

a) Nucleus
b) Ribosome
c) Golgi apparatus
d) Vacuole

Q5. Which organelle is directly involved in protein synthesis?

a) Ribosome
b) Lysosome
c) Chloroplast
d) Mitochondrion

Q6. Which organelle is responsible for modifying and packaging many cellular products?

a) Golgi apparatus
b) Nucleus
c) Mitochondrion
d) Cell wall

Q7. The movement of water through a selectively permeable membrane is called:

a) diffusion
b) osmosis
c) respiration
d) circulation

Q8. Which of the following is characteristic of prokaryotic cells?

a) Membrane-bound nucleus
b) Membrane-bound mitochondria
c) Absence of a membrane-bound nucleus
d) Presence of chloroplasts in every cell

Q9. Which structure helps a plant cell maintain its shape and provides mechanical support?

a) Ribosome
b) Cell wall
c) Nucleus
d) Cytoplasm

Q10. Which organelle is associated with the breakdown of cellular waste and damaged components?

a) Lysosome
b) Chloroplast
c) Ribosome
d) Golgi apparatus

Section B — Very Short Answer Questions

5 × 2 = 10 Marks

Q11. State any two important statements of cell theory.

Q12. What is the role of the plasma membrane?

Q13. What is the function of mitochondria?

Q14. Why are chloroplasts called specialised organelles of plant cells?

Q15. What is the difference between a unicellular and a multicellular organism?

Section C — Short Answer Questions

4 × 3 = 12 Marks

Q16. Explain the importance of the nucleus in a cell.

Q17. Differentiate between rough endoplasmic reticulum and smooth endoplasmic reticulum.

Q18. Explain why cells need different organelles to perform their activities.

Q19. What happens to an animal cell when placed in a hypotonic solution? Explain why.

Section D — Competency-Based Questions

2 × 4 = 8 Marks

Q20. A student prepares two slides using onion peel and cheek cells. Under the microscope, the onion cells appear rectangular and have a distinct outer boundary, while the cheek cells appear irregular and lack that rigid outer boundary.

Answer the following:

a) Which sample is from a plant?
b) Which sample is from an animal?
c) Name the rigid outer boundary visible in the onion cells.
d) Why is this boundary absent in cheek cells?

Q21. A cell is placed in a solution and gradually loses water. Its contents shrink, while the rigid outer boundary remains in its original position.

a) Is the surrounding solution likely hypotonic or hypertonic?
b) In which direction does water move?
c) What process is involved?
d) What is the condition of the plant cell called?

Section E — Long Answer Questions

2 × 5 = 10 Marks

Q22. Compare prokaryotic and eukaryotic cells on the basis of their nucleus, cell size, genetic material and membrane-bound organelles. Give one example of each.

Q23. Describe the major differences between plant and animal cells. Explain how the cell wall, chloroplasts and vacuoles contribute to the structure and function of plant cells.

SOLUTIONS

Section A — Answers

1. a) Robert Hooke
2. b) Cells are the basic structural and functional units of living organisms.
3. c) Plasma membrane
4. a) Nucleus
5. a) Ribosome
6. a) Golgi apparatus
7. b) Osmosis
8. c) Absence of a membrane-bound nucleus
9. b) Cell wall
10. a) Lysosome

Section B — Solutions

Q11. Cell Theory

Two important statements of cell theory are:

1. All living organisms are composed of one or more cells.
2. The cell is the basic structural and functional unit of life.

The cell theory also states that new cells arise from pre-existing cells.

Q12. Plasma Membrane

The plasma membrane forms the boundary of the cell and regulates the movement of substances between the cell and its surroundings.

It is selectively permeable, meaning that it controls which substances can enter or leave the cell.

Q13. Mitochondria

Mitochondria are important sites of cellular respiration. They help release usable energy from food, which can then be used for various activities of the cell.

Q14. Chloroplasts

Chloroplasts are specialised organelles found in photosynthetic plant cells. They contain chlorophyll, which absorbs light energy needed for photosynthesis.

Q15. Unicellular and Multicellular Organisms

A unicellular organism consists of a single cell that performs all essential life processes.

A multicellular organism consists of many cells, which may become specialised to perform different functions.

Section C — Solutions

Q16. Importance of the Nucleus

The nucleus is a membrane-bound organelle found in eukaryotic cells.

Its major functions include:

• storing genetic material;
• controlling and coordinating many cellular activities;
• regulating processes such as growth and cell division;
• helping transmit hereditary information to new cells.

Because it contains important genetic information and influences cellular activities, the nucleus plays a central role in the organisation of a eukaryotic cell.

Q17. Rough ER and Smooth ER

Q18. Why Do Cells Need Different Organelles?

Cells carry out many different activities, such as obtaining energy, making proteins, transporting substances, storing materials and removing waste.

Different organelles are specialised for different functions. For example:

• mitochondria help release energy;
• ribosomes make proteins;
• Golgi apparatus modifies and packages materials;
• lysosomes help break down unwanted materials.

The division of functions among organelles makes cellular activities more organised and efficient.

Q19. Animal Cell in a Hypotonic Solution

A hypotonic solution has greater availability of water outside the cell than inside.

Water enters the animal cell through osmosis. Since an animal cell does not have a rigid cell wall, it may swell considerably and can eventually burst if too much water enters.

Section D — Solutions

Q20. Onion Peel and Cheek Cells

a) The onion peel is from a plant.

b) The cheek cells are from an animal.

c) The rigid outer boundary is the cell wall.

d) Cheek cells are animal cells and animal cells do not possess a cell wall. They have a plasma membrane as their outer boundary.

Q21. Water Loss from a Plant Cell

a) The surrounding solution is likely hypertonic.

b) Water moves out of the plant cell into the surrounding solution.

c) The process is osmosis.

d) The condition is called plasmolysis, in which the cell contents shrink and the plasma membrane pulls away from the cell wall.

Section E — Solutions

Q22. Prokaryotic and Eukaryotic Cells

Prokaryotic cells are generally simpler in organisation, while eukaryotic cells contain a nucleus and several specialised membrane-bound organelles.

Q23. Plant Cells and Animal Cells

Plant and animal cells are both eukaryotic and contain common structures such as the plasma membrane, cytoplasm, nucleus, mitochondria, ribosomes, endoplasmic reticulum and Golgi apparatus.

However, plant cells have some distinctive structures.

Cell wall:
The cell wall is a rigid outer layer surrounding the plasma membrane. It provides mechanical support, protection and helps maintain the shape of the plant cell.

Chloroplasts:
Chloroplasts contain chlorophyll and are present in photosynthetic plant cells. They capture light energy and carry out photosynthesis.

Vacuole:
Plant cells generally contain a large central vacuole filled with cell sap. It stores water and dissolved substances and helps maintain internal pressure, contributing to the firmness of the plant.

Animal cells do not have a cell wall or chloroplasts and generally have smaller vacuoles.

Thus, the structures found in plant cells help them remain supported and carry out photosynthesis, while animal cells have a more flexible structure suited to their functions.