Search for a pond with greenish water. Collect some of the green fibres from the water. Put the fibres in a petridish and wash them clean with water. Put one of the fibres in a drop of water on a glass slide and spread it out straight. Put a cover-slip over the slide and observe under a compound microscope.

Activity 1 : Take a conical flask and collect the water in it from a pond having stagnent water and aquatic plants. Add some wheat grans and aquatic plants to it. Keep it for 3-4 days so that wheat grains and plants will decompose. Early in the morning on fourth day, take a glass slide and put a drop of that water over it. Carefully, put a cover-slip on that drop and observe under compound microscope.

Activity 2 : Bring the active dry yeast powder from market . Take 50ml lukewarm water in a conical flask. Add 5gm of active dry yeast powder and 10 gm table sugar to that water andmix the mixture well. Keep the flask in warm place and after an hour take a drop of that mixture on a clean glass slide. Put a cover-glass on that drop and observe it under the compound microscope.

Bring ‘active dry yeast’ from the market. Mix a spoonful of yeast, two poonfuls sugar with «sufficient quantity of lukewarm water in a bottle. Fix a colourless, transparent balloon on the mouth of that bottle. Take a drop of the solution from the bottle on a glass slide, put a cover -slip over it and observe it under the compound microscope. Store the solution in the bottle carefully.

Take a plantlet of fenugreek, groundnut or any other bean and sterilize it with a 3 to 5% solution of hydrogen peroxide. Afterwards, keep it in a 70% solution of ethyl alcohol for 4 to 5 minutes. Clean the roots with sterile water and take thin sections of the root nodules. Select good section and place it in a solution of safranin for 2 to 3 minutes. Place the stained section on a glass slide, cover it with a coverslip and observe it under the compound microscope.

Collect different water samples of fresh water. Mount them on a glass slide and observe under a compound microscope. Try to identify the organisms which are visible under it.

Take two big glasses of water . Add 4-5 spoonfuls of salt to the water in one glass and dissolve it completely . Now place a potato in the water in the second glass . The potato will sink . Take out the potato from that glass and put it in the salt water and observe .

Activity-based question : Activity : Take a small drop of curd or buttermilk on a clean glass slide. Dilute it with a little water. Carefully keep a coverslip. Observe ot under high power of compound microscope. What did you see ?

Answer the following questions : Study the following procedure and answer the questions below: (i)Take 3 spheres of iron , copper and lead of equal mass. (ii) Put all the 3 spheres in boiling water in a beaker for some time . (iii) Take 3 spheres out of the water . Put them immediately on a thick slab of wax. (iv) Note the depth that each sphere goes into the wax. Which property of a substance can be studied with this procedure ?

Answer the following questions : Study the following procedure and answer the questions below: (i) Take 3 spheres of iron , copper and lead of equal mass. (ii) Put all the 3 spheres in boiling water in a beaker for some time . (iii) Take 3 spheres out of the water . Put them immediately on a thick slab of wax. (iv) Note the depth that each sphere goes into the wax. Explain the rule of heat exchange with this property.