BIOLOGY
CLASSIFICATION OF CARBOHYDRATES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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absence of reducing sugar
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presence of reducing sugar
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presence of starch
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absence of starch
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Detailed explanation-1: -The result is positive. According to the observation the food sample or the potato slice turned to blue-black on adding the iodine solution. This proves the presence of starch in the given plant source.
Detailed explanation-2: -On adding the iodine solution to starch, the two react to produce a blue-black color. Q. Rice is a rich source of starch and iodine gives blue black colour with starch.
Detailed explanation-3: -Using an iodine solution, you can test for the presence of starch. When starch is present, the iodine changes from brown to blue-black or purple.
Detailed explanation-4: -A positive result for the iodine test (starch is present) was a colour change ranging from violet to black; a negative result (no starch) was the yellow colour of the iodine solution.