NCERT Solutions

Complete the journey of food through the alimentary canal by filling up the boxes with appropriate parts-

Sahil placed some pieces of chapati in test tube A. Neha placed chewed chapati in test tube B, and Santushti took boiled and mashed potato in test tube C . All of them added a few drops of iodine solution to their test tubes-A, B, and C, respectively. What would be their observations? Give reasons.

Anil claims to his friend Sanvi that respiration and breathing are the same process. What question(s) can Sanvi ask him to make him understand that he is not correct?

Which of the following statements is correct and why?

Anu: We inhale air. Shanu: We inhale oxygen. Tanu: We inhale air rich in oxygen.

We often sneeze when we inhale a lot of dust-laden air. What can be possible explanations for this?

Paridhi and Anusha of Grade 7 started running for their morning workout. After they completed their running, they counted their breaths per minute. Anusha was breathing faster than Paridhi. Provide at least two possible explanations for why Anusha was breathing faster than Paridhi.

Yadu conducted an experiment to test his idea. He took two test tubes, A and B , and added a pinch of rice flour to the test tubes, halffilled with water and stirred them properly. To test tube B, he added a few drops of saliva. He left the two test tubes for $35-45 \mathrm{~min}$. After that, he added iodine solution into both the test tubes. Experimental results are as shown in Fig. 9.15. What do you think he wants to test?

Rakshita designed an experiment taking two clean test tubes, A and B and filled them with lime water as shown in the figure. In test tube A, the surrounding air that we inhale was passed on by sucking air from the pipe, and in test tube B, the exhaled air was blown through the pipe (Fig. 9.16). What do you think she is trying to investigate? How can she confirm her findings?