Investigating osmosis in potato strips

 

Osmosis is the movement of water molecules from a region of higher water concentration (dilute solution) to a region of lower water concentration (concentrated solution) through a selectively permeable membrane.

Potato cells have partially permeable membranes. Depending on the concentration of the surrounding salt solution, water moves into or out of the potato cells.

Materials Required

• Fresh potato

• cork borer

• Ruler

• Weighing balance

• 5 beakers/test tubes

• Salt (NaCl)

• Water

• Tissue paper

• Labels

Procedure

1. Cut fifteen potato strips of equal length and thickness (e.g., 2 cm )

2. Measure and record the initial length of each strip.

3. Prepare salt solutions of different concentrations:

• 0 g/50 ml
• 1 g/50 ml
• 2g/50 ml
• 3g/50ml
• 4g/50 ml

4. Label the beakers and pour equal volumes of each solution into them.

5. Place three potato strip into each beaker.

6. Leave them for about 20 minutes.

7. Remove the strips, gently blot them dry with tissue paper.

8. Measure and record the final length of each strip.

The experiment demonstrates that osmosis causes water to move across the potato cell membrane depending on the concentration of the surrounding salt solution. Water enters the cells in dilute solutions and leaves the cells in concentrated solutions.

Class VIII Law of conservation of energy through simple pendulum

 

As a part of discussion of Energy, In a simple pendulum with no friction, mechanical energy is conserved.  Total mechanical energy is a combination of kinetic energy and gravitational potential energy.   As the pendulum swings back and forth, there is a constant exchange between kinetic energy and gravitational potential energy. At its starting point, all of the swing’s mechanical energy is potential energy. It has no kinetic energy because it’s not moving.

As the swing moves downward, some of its potential energy changes into kinetic energy.

At its bottommost point, the swing’s kinetic energy is at its maximum because it is moving at its fastest speed. Its potential energy is at a minimum because the swing is at its lowest point.

The learners used the pendulum and observed the rotation of pendulum to get the concept of Energy conservation. 

Mystery box challenge - Welcoming students class VII

 

Students picked a ticket from mystery box containing folded slips having challenges like:

• Make everyone laugh.

• Describe your vacation using only three words.

• Draw your favourite holiday memory in 30 seconds.

• Give someone a compliment.

• Tell a joke.

• Share one goal for this year.

The activity was fun and students enjoyed alot!

WELCOME BACK TO SCHOOL AFTER SUMMER BREAK

 Dear Students,

I hope you had a wonderful and refreshing summer break filled with fun, learning, and memorable moments with your family and friends.As we begin a new academic term, I would like to warmly welcome each one of you back to school. We are excited to see your smiling faces, hear about your summer experiences, and embark on another exciting journey of learning together.This new term brings fresh opportunities to explore new ideas, develop new skills, and achieve your goals. Let us start with enthusiasm, curiosity, and a positive attitude. Remember, every day is a chance to learn something new and grow into the best version of yourself.We look forward to an engaging, productive, and successful term ahead. Let us work together to make this school year enjoyable, inspiring, and full of achievements.

Welcome back, and let the learning begin!

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.