Solutions - CBSE Class 10 Sample Paper for 2022 Boards - Science [MCQ]

Class 10
Solutions to CBSE Sample Paper - Science Class 10

Case Base Question 

The Figure shown below represents an activity to prove the requirements for photosynthesis. During this activity, two healthy potted plants were kept in the dark for 72 hours. After 72 hours, KOH is kept in the watch glass in setup X and not in setup Y. Both these setups are air tight and have been kept in light for 6 hours. Then, Iodine Test is performed with one leaf from each of the two plants X and Y.

Q 52 - Case - potted plants were kept in the dark - Teachoo.jpg


This experimental set up is used to prove essentiality of which of the following requirements of photosynthesis?  

(A) Chlorophyll 

(B) Oxygen 

(C) Carbon dioxide 

(D) Sunlight 


Answer - 

To perform photosynthesis, plants need three things: carbon dioxide, water, and sunlight .


In the experiment the plants are kept airtight with the presence of potassium hydroxide which absorbs all the carbon dioxide present in the jar, to prove the essentiality of carbon dioxide. 

Thus, this experiment is used to prove essentiality of Carbon Dioxide

Potassium Hydroxide (KOH) absorbs Carbon Dioxide in Container X - Teachoo.jpg

So, the correct answer is (c)  


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CA Maninder Singh is a Chartered Accountant for the past 14 years and a teacher from the past 18 years. He teaches Science, Economics, Accounting and English at Teachoo