Boojho wanted to test the presence of starch in leaves- He performed the following steps-He did not get the expected result- Which step did he miss- Explain- -

You visited us 3 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard VII

Biology

Photosynthesis

Boojho wanted...

Question

Boojho wanted to test the presence of starch in leaves. He performed the following steps.

He took a leaf and boiled it in water.

He placed the leaf in a petri dish and poured some
iodine over it.

He did not get the expected result. Which step did he miss? Explain.

Open in App

Solution

The following steps are to be followed while testing for starch:

Take a leaf in a beaker and boil the leaf. And pour spirit/alcohol to completely immerse the leaf in a test-tube.

Now, place the leaf in a beaker half filled with water.

Heat the beaker till all the green colour from the leaf comes out.

Take out the leaf carefully and wash it in water.

Place it on a watch glass and pour some iodine solution over it.

Boojho missed the step where he was supposed to
boil the leaf in alcohol.

Suggest Corrections

Similar questions

A candidate studied the importance of certain factors in photosynthesis. He took a potted plant and kept it in the dark for over 24 hours. In the early hours of the next morning, he covered one of the leaves with dark paper in the centre only. Then he placed the plant in sunlight for a few hours and tested the leaf which was covered with black paper for starch.

(a) What aspect of photosynthesis was being investigated ?

(b) Is there any control in this experiment ? If so, state it.

(d) Describe step by step, how the candidate proceeded to test leaf for the presence of starch.

Q. In an experiment to test the presence of starch in a leaf, the plucked leaf is first boiled in water for a few minutes. This is an important step in the experiment because it :
(1) converts glucose made in the leaf into starch
(2) dissolves chlorophyll present in the green leaf
(3) extracts starch to destarch the leaf
(4) makes the leaf more permeable to iodine solution

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. In an experiment to test the presence of starch in a leaf, the leaf is boiled in alcohol for a few minutes using a water bath. This is an essential step in the experiment because alcohol:
(1) softens the leaf
(2) disinfects the leaf
(3) allows iodine to enter the leaf
(4) dissolves chlorophyll from leaf

Q. Anurag wanted to test for the presence of starch in different food items. He had four different chemicals. Which of the following should he use for his test?
(a) iodine
(b) an acid
(c) copper sulphate
(d) potassium hydroxide

Join BYJU'S Learning Program

Boojho wanted to test the presence of starch in leaves.​ He performed the following steps.​ He took a leaf and boiled it in water.​ He placed the leaf in a petri dish and poured some​ iodine over it. ​ He did not get the expected result.​ Which step did he miss? Explain. ​

Boojho wanted to test the presence of starch in leaves. He performed the following steps.

He took a leaf and boiled it in water.

He placed the leaf in a petri dish and poured some
iodine over it.

He did not get the expected result. Which step did he miss? Explain.