Not all cells are the same. In this activity,
you will compare the structure of bacterial cells, plant cells, and animal cells by studying diagrams and identifying
which structures are present in each type.
Aim
To compare the structure of bacterial, plant, and animal cells by observing diagrams and filling in Table 2.1.
Materials Required
NCERT Science textbook (Class 9, Chapter 2)
Figure 2.10 (a) — Bacterial cell diagram
Figure 2.10 (b) — Plant cell diagram
Figure 2.10 (c) — Animal cell diagram
Notebook and pen
Coloured pencils (optional, for drawing)
Procedure
Open your NCERT textbook: Turn to Chapter 2 and locate Figure 2.10 on the relevant page.
Study the bacterial cell diagram (Fig 2.10a): Carefully observe all the structures shown.
Notice which parts are present and which are absent.
Study the plant cell diagram (Fig 2.10b): Identify all visible structures and
organelles.
Study the animal cell diagram (Fig 2.10c): Compare it with the plant and bacterial cells.
Note the differences.
Fill Table 2.1: In your notebook, copy the table and mark ✓ (present) or ✗ (absent) for each
structure in each cell type.
Identify prokaryotic vs eukaryotic: Based on the presence or absence of a well-defined nucleus,
classify cells as prokaryotic or eukaryotic.
Table 2.1: Comparison of Cell Structures (Completed)
S.No.
Cell Structures
Bacterial Cell
Plant Cell
Animal Cell
1
Cell membrane
✓ Present
✓ Present
✓ Present
2
Cell wall
✓ Present
✓ Present
✗ Absent
3
Cytoplasm
✓ Present
✓ Present
✓ Present
4
Well-defined nucleus
✗ Absent
✓ Present
✓ Present
5
Primitive nucleus (nucleoid)
✓ Present
✗ Absent
✗ Absent
6
Membrane-bound organelles (mitochondria, chloroplasts, Golgi, ER, etc.)
✗ Absent
✓ Present
✓ Present
Quick Memory Tip
ALL cells have: Cell membrane + Cytoplasm ONLY bacterial cells have: Nucleoid (no nucleus, no organelles) ONLY plant cells have: Cell wall + Chloroplasts + Large vacuole Plant and animal cells both have: Nucleus + Membrane-bound organelles
Additional Observations
Bacterial Cell
Very small (1-10 µm)
No nucleus, has nucleoid
No organelles
Circular DNA
Simple structure
Prokaryotic
Plant Cell
Larger (10-100 µm)
Well-defined nucleus
Has chloroplasts
Large central vacuole
Cell wall present
Eukaryotic
Animal Cell
Larger (10-100 µm)
Well-defined nucleus
No chloroplasts
Small/no vacuole
No cell wall
Eukaryotic
Result
Based on Table 2.1:
Bacterial cells are prokaryotic
— they lack a well-defined nucleus and membrane-bound organelles
Plant cells and animal cells are eukaryotic
— they have a well-defined nucleus enclosed in a nuclear membrane and contain membrane-bound organelles
All three cell types have cell membrane and cytoplasm
Inference
Key Conclusions
Universal features: All cells (bacterial, plant, animal) have cell membrane and cytoplasm — these
are essential for life
Prokaryotic cells are simpler: Bacteria are smaller, lack nucleus, and have no organelles
Eukaryotic cells are complex: Plant and animal cells are larger and have organized
organelles for different functions
Evolution connection: Prokaryotic cells appeared first on Earth; eukaryotic cells evolved later and
are more advanced
No nucleus — genetic material (DNA) is not enclosed in a membrane
DNA is located in a region called nucleoid
No membrane-bound organelles (no mitochondria, ER, Golgi, etc.)
Very small size (typically 1-10 micrometres)
Simple internal structure
Examples: All bacteria and blue-green algae (cyanobacteria)
What Makes a Cell Eukaryotic?
Eukaryotic cells (eu = true, karyon = nucleus):
Have a well-defined nucleus enclosed by a nuclear membrane
DNA is organized into chromosomes inside the nucleus
Contain membrane-bound organelles (mitochondria, ER, Golgi, lysosomes, etc.)
Larger size (typically 10-100 micrometres)
Complex internal organization with division of labour among organelles
Examples: All plants, animals, fungi, protozoans
Key Structural Differences
Feature
Prokaryotic
Eukaryotic
Nucleus
Absent (nucleoid region)
Present with nuclear membrane
Size
1-10 µm (small)
10-100 µm (large)
Organelles
No membrane-bound organelles
Many specialized organelles
DNA location
In nucleoid (not enclosed)
In nucleus (enclosed)
Cell division
Binary fission (simple)
Mitosis/Meiosis (complex)
Real-Life Application
Understanding cell types helps in many ways: Antibiotics target prokaryotic cells (bacteria) without harming our eukaryotic
cells. This is why antibiotics can kill harmful bacteria in your body without destroying your own cells. They exploit the
structural differences between prokaryotic and eukaryotic cells. Learn more about
how cells work.
Tips for This Activity
Study each diagram carefully before filling the table
Don't confuse nucleoid (in prokaryotes) with nucleus (in eukaryotes)
Remember: membrane-bound organelles means organelles with their own membranes (like mitochondria, ER)
Mark clearly with ✓ or ✗ — avoid unclear symbols
Cross-check your answers with the diagrams before submitting
5 Important Viva Questions
Q1. What is a nucleoid? How is it different from a nucleus?
Nucleoid: A region in prokaryotic cells (bacteria) where genetic material (DNA) is located, but it is
not enclosed by a membrane.
Differences from nucleus:
Nucleoid (Prokaryotic)
Nucleus (Eukaryotic)
No membrane surrounding it
Enclosed by double nuclear membrane
DNA is circular and not organized
DNA organized into chromosomes
DNA directly in cytoplasm
DNA separated from cytoplasm
No nucleolus
Contains nucleolus
Simple way to remember: Nucleoid = "nuclear-like region" without a membrane.
Nucleus = proper compartment with membrane protection.
Q2. Which cell has both cell membrane AND cell wall? Why do they need both?
Both bacterial cells and plant cells have cell membrane AND
cell wall.
Why they need both:
Cell membrane:
Controls what enters and leaves the cell (selectively permeable)
Regulates exchange of materials
Essential for all life processes
Protects the cytoplasm and organelles
Cell wall:
Provides structural support and rigidity
Maintains cell shape
Protects against physical damage
Prevents cell from bursting when water enters
Fully permeable (allows everything through)
Analogy: Think of cell membrane as a security guard (controls entry) and cell wall as a brick wall
(provides structure). Both serve different but important purposes. Learn more about
cell membrane functions.
Q3. Why is a bacterial cell called prokaryotic? What does "prokaryotic" mean?
A bacterial cell is called prokaryotic because it does not have a well-defined nucleus or
membrane-bound organelles.
Meaning of "prokaryotic":
Pro = before, primitive
Karyon = nucleus
Prokaryotic = "before nucleus" or "primitive nucleus"
It means cells that existed before the evolution of a true nucleus
Characteristics that make bacterial cells prokaryotic:
No nucleus: Genetic material is not enclosed in a nuclear membrane
Nucleoid region: DNA is present in a primitive region called nucleoid
No organelles: No mitochondria, ER, Golgi apparatus, or other membrane-bound organelles
Simple structure: Less complex internal organization
Small size: Usually 1-10 micrometres
Prokaryotic cells were the first forms of life on Earth and are evolutionarily older than eukaryotic cells.
See detailed comparison at Prokaryotic vs Eukaryotic Cells.
Q4. Name one organelle present in plant cells but absent in animal cells. Why is it important?
Chloroplasts are present in plant cells but absent in animal cells.
Why chloroplasts are important:
Photosynthesis: Chloroplasts contain chlorophyll (green pigment) and carry out photosynthesis
Food production: They convert sunlight, water, and carbon dioxide into glucose (food) and oxygen
Energy source: This glucose provides energy for the plant to grow and survive
Oxygen release: Photosynthesis releases oxygen as a byproduct, which is essential for all living beings
Why animal cells don't have chloroplasts:
Animals cannot make their own food
Animals are heterotrophs — they get food by eating plants or other animals
They don't need chloroplasts because they don't perform photosynthesis
Animals get energy by breaking down food in mitochondria, not by making food
Other examples: Large central vacuole and cell wall are also present in plant cells but absent in
animal cells. Learn more about organelle functions.
Q5. What does "membrane-bound organelles" mean? Give two examples.
Membrane-bound organelles are specialized structures inside cells that are surrounded by their own
protective membrane (similar to the cell membrane).
Why they're called "membrane-bound":
Each organelle has its own membrane made of lipid bilayer
This membrane separates the organelle from the cytoplasm
Allows the organelle to maintain specific internal conditions
Enables specialized functions without interference
Two examples:
1. Mitochondria (present in both plant and animal eukaryotic cells):
Surrounded by double membrane
Called "powerhouse of the cell"
Produces energy (ATP) through cellular respiration
Has its own DNA
2. Endoplasmic Reticulum / ER (present in eukaryotic cells):
Network of membrane-bound tubes and sacs
Helps in protein synthesis and lipid formation
Two types: Rough ER (with ribosomes) and Smooth ER (without ribosomes)
Other examples:
Nucleus (has nuclear membrane)
Golgi apparatus
Lysosomes
Chloroplasts (in plant cells)
Vacuoles
Important: Prokaryotic cells (bacteria) do NOT have any membrane-bound organelles. This is one of
the main differences between prokaryotic and eukaryotic cells. See all
organelles explained.
Key Terms to Remember
Prokaryotic Cell
Cell without a well-defined nucleus or membrane-bound organelles; DNA in nucleoid region. Example: Bacteria.
Eukaryotic Cell
Cell with a well-defined nucleus enclosed by nuclear membrane and containing membrane-bound organelles. Example: Plant, animal cells.
Nucleoid
Primitive nucleus-like region in prokaryotic cells where DNA is located, not enclosed by membrane.
Nucleus
Membrane-bound organelle in eukaryotic cells that contains genetic material (DNA) organized into chromosomes.
Membrane-bound Organelles
Specialized cell structures surrounded by their own membrane (mitochondria, ER, Golgi, etc.); absent in prokaryotes.
Chloroplast
Green organelle in plant cells containing chlorophyll; site of photosynthesis; absent in animal cells.
Cell Wall
Rigid outer layer in bacterial and plant cells providing support and protection; absent in animal cells.
Cytoplasm
Jelly-like substance filling the cell between membrane and nucleus; present in all cells.
