If a leaf has undergone photosynthesis, what would be the result of the starch test on this leaf?

The whole leaf would turn purple-yellow in colour.

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The whole leaf would turn dark green in colour.

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The whole leaf would turn brown in colour.

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The whole leaf would turn blue-black in colour.

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Solution

The correct option is D The whole leaf would turn blue-black in colour.
The end result of a starch test on a leaf would make it either brown or blue-black. If starch has been produced (that is if photosynthesis has occurred), the leaf would turn blue-black, otherwise, it would remain brown.

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Similar questions

Q. A portion of destarched leaf of a potted plant was covered with a black strip of paper. The plant was then exposed to sunlight for six hours and then tested for starch. It was observed that:
(1) both covered and uncovered parts of leaf turned blue-black
(2) both covered and uncovered parts of leaf turned yellow-brown
(3) only the uncovered part of leaf turned blue-black
(4) only the covered part of leaf turned blue-black

Q. Arun carried out the following experiment with a croton (variegated) leaf. He drew the leaf in his notebook marking the green and the non-green area. He put the leaf in hot alcohol till all the green colour came out and the leaf turned white. He then washed the leaf in water and covered the leaf in iodine solution.
(a) Why did he draw the leaf and mark the green and non-green areas?
(b) What was the colour change in iodine solution?
(c) Which portions of the leaf show colour change?
(d) what can you conclude from this experiment?

Q. A star-shaped figure was cut in the black paper strip used for covering the leaf of a destarched plant used for demonstrating that light is necessary for photosynthesis. At the end of the experiment when the leaf was tested for starch with iodine, the star-shaped figure on the leaf was found to be:

(1) colourless
(2) green in colour
(3) brown in colour
(4) blue-black in colour

Consider the leaf of a plant shown in the figure below:

After destarching the plant, it was partially covered with a lightproof paper (as shown in the figure above), and the entire plant kept in the sunlight for 3-4 hours. After this, the starch test was carried out on the leaf. Which of the following would the leaf appear like at the end of the starch test?

Q. Both the plants 'A' and 'B' were kept in sunlight after watering. The part of the leaf of plant 'B' which was inserted in the glass bottle containing KOH(Potassium hydroxide) did not turn blue in the iodine test/ starch test, indicating the absence of starch. The part of the leaf outside the bottle turns blue in the said test. Photosynthesis didn't occur in that part of the leaf due to the non-availability of _________.

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If a leaf has undergone photosynthesis, what would be the result of the starch test on this leaf?

The correct option is D The whole leaf would turn blue-black in colour.The end result of a starch test on a leaf would make it either brown or blue-black. If starch has been produced (that is if photosynthesis has occurred), the leaf would turn blue-black, otherwise, it would remain brown.

The correct option is D The whole leaf would turn blue-black in colour.
The end result of a starch test on a leaf would make it either brown or blue-black. If starch has been produced (that is if photosynthesis has occurred), the leaf would turn blue-black, otherwise, it would remain brown.