PDF chapter test TRY NOW
Take two test tubes. Label them ‘A’ and ‘B’. In test tube ‘A’ put one teaspoonful of boiled rice; in test tube ‘B’ keep one teaspoonful of boiled rice after chewing it for 3 to 5 minutes. Add 3–4 mL of water in both the test tubes (Fig. 2.4). Now pour 2–3 drops of iodine solution in each test tube and observe. Why is there a change in colour in the test tubes? Discuss the results with your classmates and your teacher.
Choose the correct results:
1. Test tube A: Boiled rice (un-chewed) + water + iodine -
2. Test tube B: Boiled rice (chewed) + saliva + water + iodine -
Answer variants:
Blue-black color (indicating presence of starch)
Lighter color or no color change (indicating partial digestion of starch into sugars by saliva)
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