What is CSEEL and what does it offer?

CSEEL (Center for Scientific Exploration and Experiential Learning) is a premier Indian STEM educational initiative offering hands-on science experiments, 3D live laboratory simulations, curriculum-aligned project kits, teacher training workshops, and national science conclaves aligned with NEP 2020.

How does CSEEL support NEP 2020 experiential learning?

CSEEL shifts education from rote memorization to active inquiry and hands-on experimentation. Students observe, build, analyze, and apply scientific concepts to real-world challenges, developing critical thinking and scientific temper as envisioned by NEP 2020.

What subjects and classes are covered in CSEEL simulations and experiments?

CSEEL provides comprehensive physics, chemistry, biology, environmental science, and applied robotics experiments and virtual simulations for students from Class 6 through Class 12, mapped to CBSE, ICSE, and state curricula.

How can schools, educators, and students access CSEEL programs?

Institutions, teachers, and students can explore live simulations, order DIY lab kits, register for national seminars, and join the CSEEL EduNetwork by visiting https://www.cseel.org.

Distribution and Density of Stomata on Leaf Surfaces

Experiment video

What you will learn

Compare the distribution, frequency, and density of stomata on the upper (adaxial) and lower (abaxial) epidermis of a dorsiventral leaf (Hibiscus / Petunia) and an isobilateral leaf (Grass / Maize).

Materials needed

Fresh leaves: Hibiscus / Nerium (dorsiventral) and Grass / Zea mays (isobilateral) each
Fresh leaves: Hibiscus / Nerium (dorsiventral) and Grass / Zea mays (isobilateral) each
₹50
What is it?
Fresh leaves of Tradescantia / Rhoeo discolor and Hibiscus rosa-sinensis.
Specifications
Rhoeo discolor
Features purple lower epidermis giving natural high-contrast stomatal viewing
Condition
Fresh turgid leaves harvested in morning with open stomata
Colorless clear nail polish or quick-drying collodion bottle
Colorless clear nail polish or quick-drying collodion bottle
₹95
What is it?
Calibrated Glass Stage Micrometer and Eyepiece Reticle.
Specifications
Scale Length
1.0 mm total scale
Divisions
100 divisions (1 division = 0.01 mm = 10 μm)
Accuracy
Class A optical calibration standard
Clear transparent cellophane tape (Scotch tape) roll
Clear transparent cellophane tape (Scotch tape) roll
₹140
What is it?
Safranin O biological stain (1% aqueous) and analytical mountant.
Specifications
Stain
1.0% certified Safranin O in distilled water
Mountant
50% glycerol in distilled water
Clean glass microscope slides and cover slips box
Clean glass microscope slides and cover slips box
₹185
What is it?
Standard laboratory apparatus used in Distribution and Density of Stomata on Leaf Surfaces.
Specifications
Category
Biology Apparatus
Grade
CBSE / NEP 2020 Laboratory Standard
Compound Microscope with calibrated ocular micrometer grid
Compound Microscope with calibrated ocular micrometer grid
₹230
What is it?
Standard laboratory apparatus used in Distribution and Density of Stomata on Leaf Surfaces.
Specifications
Category
Biology Apparatus
Grade
CBSE / NEP 2020 Laboratory Standard
Fine Forceps and Scissors set
Fine Forceps and Scissors set
₹275
What is it?
Standard laboratory apparatus used in Distribution and Density of Stomata on Leaf Surfaces.
Specifications
Category
Biology Apparatus
Grade
CBSE / NEP 2020 Laboratory Standard

Tick items as you collect them. Tap + to see the product, specifications and buy options.

Stay safe

Apply a thin, even coat of nail polish; thick coats take too long to dry and produce blurred optical impressions.
Allow polish to dry thoroughly before peeling with tape to avoid smudging.
Count multiple microscopic fields (at least 5 fields) and average to obtain statistically reliable stomatal counts.
Avoid leaf veins when counting stomatal density.

Steps

0 of 7 steps done

1Select a clean, turgid leaf and dry the surface with tissue paper.
Observation
Tear fresh dorsiventral leaf (Hibiscus / Tradescantia) obliquely with a quick jerk to expose thin lower transparent epidermis.
Safety
Select healthy, turgid leaves from well-watered sunlit plants.
2Paint a thin, uniform patch (~1 cm²) of clear nail polish on the upper epidermis of the leaf.
Observation
Peel lower epidermal strip with fine forceps; mount in drop of water on clean slide; repeat for upper epidermis.
Safety
Keep peels completely submerged in water to prevent guard cell plasmolysis.
3Paint a similar patch on the lower epidermis.
Observation
Stain peel lightly with 1% Safranin for 1 minute; wash excess stain; mount in drop of 50% glycerine with coverslip.
Safety
Lower coverslip gently with needle to avoid trapping distracting air bubbles.
4Allow the nail polish to dry completely for 10-15 minutes into a tough, clear peel.
Observation
Calibrate microscope field of view under 400× using stage micrometer (Field diameter = 0.50 mm => Area = 0.196 mm²).
Safety
Do not scratch stage micrometer glass scale.
5Press a piece of clear cellophane tape firmly over the dried polish patch.
Observation
Count total number of stomata (S) and epidermal cells (E) across 5 random microscopic fields for both surfaces.
Safety
Count cells overlapping top and right border; ignore cells overlapping bottom and left border.
6Peel the tape away smoothly; the leaf impression (epidermal imprint showing guard cells and stomatal pores) adheres to the tape.
Observation
Calculate Stomatal Index I = [S / (E+S)] × 100; observe dramatic 10× difference between upper and lower surfaces.
Safety
Record high quality photomicrograph or clear pencil camera-lucida drawing.
7Mount the tape onto a clean glass slide and count the number of stomata per microscopic field under 40x on both surfaces.

Tap + on a step to see what you will observe and any safety tips.

Record your observations

Leaf Epidermal Surface	Average Stomata Count per Field	Average Epidermal Cells per Field	Field Area (mm² at 400×)	Stomatal Density (per mm²)
Lower Epidermis (Abaxial - Dorsiventral)	28 stomata	112 epidermal cells	0.196 mm²	142.8 stomata / mm²
Upper Epidermis (Adaxial - Dorsiventral)	3 stomata	135 epidermal cells	0.196 mm²	15.3 stomata / mm²
Isobilateral Leaf (Monocot - Grass/Oat)	18 stomata	88 epidermal cells	0.196 mm²	91.8 stomata / mm²
Upper vs Lower Ratio (Dorsiventral)	1 : 9.3 Ratio	Stomata predominantly restricted to lower shaded surface	Adaptation to minimize transpiration loss

Tap a highlighted cell to write your own observation.

Result and conclusion

Dorsiventral leaves exhibit significantly higher stomatal frequency on the lower surface (abaxial, ~185 stomata/mm²) than the upper surface (adaxial, ~20 stomata/mm²), minimizing transpirational water loss.

Stomatal Index (I) = [S / (E + S)] × 100 = [28 / (112 + 28)] × 100 = 20.0%; Density = Stomata Count / Field Area

Observation	What it means
Hypostomatic Dorsiventral Leaf	Dicot leaves (like Betel/Hibiscus) concentrate >90% of stomata on lower shaded epidermis to avoid direct evaporative solar heating.
Amphistomatic Isobilateral Leaf	Monocot leaves (like grass/wheat) held vertically have nearly equal stomatal densities on both leaf surfaces.
Stomatal Index Stability	Stomatal index I = S/(E+S) = 20.0% is a constant taxonomic parameter unaffected by environmental leaf enlargement.
Guard Cell Kidney Morphology	Dicot stomata feature reniform (bean-shaped) guard cells with thick inner walls, while monocots have dumbbell-shaped guard cells.

Stomatal Density Comparison: Upper vs Lower Leaf Epidermis

Sample readings. Replace with your own results.

Experiment photos

Before the experimentDuring the experimentResult