IMPORTANT ACTIVITY
ACTIVITY 6.1 : EXPERIMENT TO SHOW THAT CHLOROPHYLL IS NECESSARY FOR PLANTS.
Following are the steps to show that CHLOROPHYLL is necessary for photosynthesis in plants:-
- Take a variegated leaves and keep it in a dark room for 3-4 days ( so that it can get de-starched).
- Now keep the plant in sunlight for a few hours.
- Pluck a leaf of the plant and boil it in water for a few minutes.
- Now take out the leaf from water and immerse it in the alcohol.
- Put the leaf containing alcohol beaker in the water bath (as alcohol cannot be heated directly, because it is highly inflammable liquid) and boil it.
- Now the leaf has became pale, because chlorophyll is removed away by the above process.
- Put out the leaf from the alcohol and wash it thoroughly with water so it become soften
- Place the leaf in a petri-dish, and drop the Iodine solution over it.
- The green coloured of the plants turn blue-black when tested with iodine solution, while other colour leaf do not change.
- Thus we conclude that chlorophyll is necessary for plants.
ACTIVITY 6.2 : EXPERIMENT TO SHOW THAT CARBON-DIOXIDE IS NECESSARY FOR PLANTS.
Following are the steps to show that CARBON-DIOXIDE is necessary for photosynthesis in plants:-
- Take two healthy potted plants and keep it in a dark room for 2-3 days.
- Now place each plants in a separate glass plates and cover it with bell jars.
- Keep Potassium Hydroxide in one of the bell jar ( assume bell jar 'a'), and seal the bottom with vaseline so that it can become air tight.
- Now leave it for 1 day, so that the carbon dioxide of the bell jar 'a' should absorbed by the potassium hydroxide and it cannot form starch.
- Now, take out the plant and keep it in sunlight for a hour.
- And pluck the leaf from each pot and test it with Iodine solution.
- The pot kept in bell jar 'a' gets blue due to absence of starch while in the other bell jar no blue color is obtained.
- Thus we conclude THAT CARBON-DIOXIDE IS NECESSARY FOR PLANTS.
ACTIVITY 6.3 :WHAT is the action of saliva on starch ?
Procedure :-
- Take two test tube A and B and fill it with 1 ml of starch solution.
- Add 1ml of saliva to test tube A and left both test tube undisturbed for 20-3. minutes.
- Now add a drop Iodine solution to both test tube.
Observation :- Test tube having starch mixed with saliva does not change to blue colour because starch present in the test tube A got breakdown into simpler sugar particles or maltose.
- Test tube B change to blue colour, because that has only starch.
ACTIVITY 6.5.
Procedure : What happens when yeast is passed through a sugar solution or fruit juice into lime water?
Yeast is a unicellular bacteria, that carries out fermentation when it is mixed with sugar solution or fruit juice. Yeast get mix with sugar or its compound and anaerobic respiration occur, thus fermentation happen.
When lime water is passed through the gas evolved in the fermentation process, Calcium carbonate get formed.
It is especially used in the industry for making wine, alcohol or in bakery to make the dough fluffy.
