Observing cells through temporary and permanent slides CLASS -IX IGCSE

 

Observing onion peel cells under a compound microscope reveals a structured, brick-like arrangement of plant cells. Key features visible include a thick cell wall, a thin, dense nucleus, and a large, central vacuole that often pushes the cytoplasm to the cell's edge. Staining with substances like safranin or methylene blue.

Cheek cell observation involves scraping the inner mouth lining to study human squamous epithelial cells under a microscope. Cells are stained with methylene blue to reveal a central nucleus, granular cytoplasm, and a thin cell membrane, confirming the absence of a cell wall or large vacuoles, characteristic of eukaryotic animal cells.

observing red blood cells (RBCs) requires a light microscope, typically  to visualize their small  biconcave, disc-like shape, which appears pale pink/red, lacks a nucleus, and shows a "dumbbell" profile. WBC's are little larger with multi nucleated appearance.

Students prepared temporary slides on their own. They used stains to observe the onion and cheek cells and glycerol over the stained sample so that sample does not dry. Then then put coverslip over the stained samples. observed under the microscope. 

The activity was a good learning experience for the learners to make them develop their lab skills, and give them concept clarity. 

Observing Paper Chromatography

Paper chromatography is a simple technique used to separate mixtures (like ink or plant pigments) into their individual components based on their solubility in a solvent and attraction to filter paper. The mixture travels up the paper via capillary action, with faster-moving components separating from slower ones to create a "chromatogram"

Materials Needed:

• Chromatography paper (or filter paper cut into strips)
• Water-soluble markers (black, green, or brown work best)
• Solvent (Water for markers)
• Gas jar
• Pencil
• Tape or a pencil to hang the strip

Procedure:

1. Prepare the Paper: Cut the paper into a strip and use a pencil to draw a straight line about 2 cm from the bottom (baseline).
2. Spot the Sample: Place a small dot of the marker ink in the center of the pencil line. Keep the spot small to prevent smearing.
3. Set Up the Solvent: Pour a small amount of water into the beaker, ensuring the water level is below the pencil line so the ink doesn't dissolve directly into it.
4. Develop the Chromatogram: Suspend the paper in the beaker so the bottom tip touches the water.

Observation:  As water rises up the paper, it carries the dyes at different speeds, separating them. Learners observe different colored dyes ispots in the chromatogram.

Learners enjoyed the activity and understood chromatography. 

Effect of tropism on germination of seeds- IGCSE Xth

 Learners of class Xth performed an investigation in which they have observed the efffect of tropism on growth of plants through germinating cress seeds.  

They set up four petridishes

Petridish-1: Cress seeds (10 in number) , soaked cotton, water and placed in sunlight

Petridish-2: Cress seeds (10 in number), Soaked cotton, water and placed in dark

Petridish-3: Cress seeds (10 in number), soaked cotton, water and sunlight only from one point

Petridish-4: Cress seeds (10 in number), soaked cotton, water and sunlight but placed vertically

They observed

Petridish-1: Growth of seeds

Petridish-2: Growth of seeds but the leaves appear yellow in colour

Petridish-3: Growth of seeds but the leaves turned towards the source of light

Petridish-4: Growth of seeds but the leaves rise vertically up in direction of sunlight.

The investigation made students more confident in understanding of the role of auxins( plant hormone) in controlling tropic responses. 

 

Science Month Activity Class VIII

 

Learners of stage-9 performed their April month science activity in which they have to make models of futuristic gadget that can solve the problem of climate crisis. Class was divided into groups of five, with five members in four group and four members in one group. 

Group-1 showed the drones which can capture the atmospheric carbondioxide and can move into collection centre to clear its filters. From this captured carbondioxide eco bricks can be made.
Group-2 showed the hydroponics way of doing agricultre reducing transportation. 
Group-3 showed Futuristic Climate Control and Smart Weather Alert System.The aim of our project is to develop a smart system that can help reduce pollution, manage environmental changes, and provide early warnings to protect both life and nature.
Group-4 showed rainwater conservation Many roads have concrete surfaces. Because of this, rainwater cannot soak into the ground easily. When it rains, the water collects in one place.   So, cities need a smart way to manage rainwater.
Group-5 showed climate crisis is driving severe global impacts, causes severe food/water scarcity. designed a simple filtration model using two containers placed at different heights. Each layer represents a stage of purification:  Rocks stop large impurities  Soil traps smaller particles  Charcoal absorbs harmful substances and removes bad odor  Cotton acts as the final filter As seawater flows down through each layer, it becomes cleaner and cleaner. While this model does not remove salt completely, it shows how water can be purified step by step using simple materials.  

The Activity made learners more sensitized towards climate and aware all about consequences and ways of reducing it.