Experiments conducted to prove the formation of starch in plants

Q. On adding iodine to a leaf boiled in alcohol, a blue-black colour appears. This means that

1. Starch is produced in the leaf
2. Starch is not produced in the leaf
3. Glucose is produced in the leaf
4. Glucose is not produced in the leaf

Q. The following are the steps followed to perfom the Iodine test for the detection of starch production in plants.
i) Iodine solution is added
ii) Leaf that was partly covered is boiled in alcohol
iii) Potted plant with a leaf partly covered with aluminium foil is exposed to sunlight
iv) the leaf is rinsed in water

The correct sequence of steps to perform the test is

1. i, ii, iii & iv
2. iii, ii, iv & i
3. iv, iii, i & ii
4. ii, i, iii & iv

Q.

Explain the test to confirm the presence of protein in food? [5 MARKS]

Q.

The leaf is boiled in alcohol to remove _______ (chlorophyll/starch).

Q.

The presence of starch is identified by __________

1. Isotonic test

2. Alcohol test

3. None of the choices

4. Iodine test

Q. Which of the following would give a positive test with iodine solution?

1. Vitamin A
2. Starch
3. Protein
4. Butter