Explain Activity 6.1 NCERT class 10 science Life processes

Activity 6.1 NCERT class 10 science chapter 6 Life processes

Procedure: Activity asks us to put a variegated leaf plant (e.g., Money plant) in the dark for three days, and in sunlight for a few hours. Then It asks to treat it with boiling alcohol and iodine solution.

Observation: Only the green coloured part of the leaf got the blue colour with the iodine solution while the white portion of the money plant leaf did not get the blue colour.

Inference: Only the green part of the leaf photosynthesize and make starch.

Activity 6.1 NCERT class 10 science
variegated leaf before and after the experiment.

A variegated leaf contains green as well as a non-green part. The green part contains chlorophyll, while the non-green part is devoid of chlorophyll.

To begin with a fresh experiment, we put Leaf in the dark for a few days. Leaf in the dark do not photosynthesize new starch, and the plant consumes all its previous starch.
Now the leaf is put into the sun. Here chlorophyll inside the chloroplast makes new starch. A broken leaf can not transport starch to different parts of the body. So this starch now remains localized to the green area only.

We now put the leaf into boiling alcohol. A boiling solution of alcohol breaks the cell wall and chloroplast. This breakage washes the chlorophyll into the solution. As a result, leaf loses its green colour and become colourless. The colourless leaf is easy to stain with iodine.

Now, when we put this colourless leaf into an iodine solution, only the green part of the leaf turn blue.

Detailed Conclusion/Inference:

In this experiment, we see that only the green part of the leaf turn blue with iodine. So, we can say only the green part of the leaf photosynthesize and produce starch. Since the green colour of the leaf is because of chlorophyll, we can also say that only chlorophyll-containing part of the leaf makes starch.

Next:activity 6.2: Experiment to demonstrate carbon dioxide is necessary for photosynthesis.

See other activities questions from life processes chapter.


Life Processes MCQ

How do Organisms Reproduce MCQ


Exercise Solution: Life Processes.

Ref: NCERT class 10 Science, chapter 6.

variegated leaf wilki

24 thoughts on “Explain Activity 6.1 NCERT class 10 science Life processes”

  1. So, please you explained this activity properly.. And life process chapter can solve all activities in detail …and read between the lines.
    And science book all activies so, came in exam so, please solve… Ok.

  2. Qno -1 answer -it was colourless because the chlorophyll is removed from cell bye the breakdown of cell membrane by the action of boiling alcohol .

  3. Alchohol is a highly flammable substance. If it is heated directly then it will not only burn the leaf but also break the beaker and can cause damage to the person performing the activity. This is why it is heated with the help of a water bath.
    Hope this will help you!

  4. because alcohol is too votile thats why it cannot be heated directly , if done so it will catch fire and may harm the person performing the experiment .

  5. Ans 1. Green patches of leaf shall become colorless after boiling in alcohol, since all the chlorophyll will come into alcohol, leaving behind newly synthesized starch in the green patches.
    Ans 2. The color of alcohol solution will turn bluish green.
    Ans 3. Refer to Ans 1 for first part of Q3. Potassium iodide/Iodine solution is light pink to wine red in color, depending upon the concentration. Low concentration iodine solution is light pink in color. After dipping the leaf, the intensity of color of iodine solution will further reduce since a part of iodine is now taken up by starch present in the leaf.
    Test of presence of starch in a mixture, by iodine solution is a standard test method. Starch is polymer of glucose and has helical elongated-thread like structure. Iodine molecules are trapped in the intra-molecular space of starch molecule and give intense blue-black color.

  6. Q1 what is the colour of the leaf before iodine is added
    Q2 colour of the solution
    Q3 what is the colour of leaf and colour of solution (@) before starch test
    (B) after starch test

  7. Because Alcohol is highly inflammable and it will burn the leaf . So, we heat the leaf indirectly in alcohol .

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