Topic outline

    • Respiration in Organisms

      Q1. Fill in the blanks.

                                 i.        In cockroaches, air enters the body through spiracles.

                                ii.        During heavy exercise, we get cramps in the legs due to the accumulation of lactic acid.

                               iii.        Normal range of breathing rate per minute in an average adult person at rest is 15ñ18.

                               iv.        During exhalation, the ribs move downwards.

                                v.        Breathing is a part of the process of respiration.

      Q2. True/False

                                i.        During heavy exercise the breathing rate of a person slows down. False

                               ii.        Gills are well supplied with blood vessels for exchange of gases. True

                              iii.        Plants carry out photosynthesis only during the day and respiration only at night. False

                              iv.        Frogs breathe through their skins as well as their lungs. True

                               v.        The fishes have lungs for respiration. False

                              vi.        The size of the chest cavity increases during inhalation. True

      Q3. What are some common uses of Yeast?

      Ans. Some common uses of Yeast are bread, wine and beer.


      Q4. Name an organism that can survive in the absence of air.

      Ans. Yeast can survive in the absence of air.


      Q5. How do earthworms breathe?

      Ans. Earthworms breathe through their skins.


      Q6. What does a breath mean?

      Ans. A breath means one inhalation plus one exhalation.

      Q7. What is cell?

      Ans. A cell is the smallest structural and functional unit of an organism.


      Q8. What are all organisms made up of?

      Ans. All organisms are made of small microscopic units called cells.


      Q9. Name the respiratory organ of birds.

      Ans. They have lungs in their chest cavities like the human beings.

      Q10. What forms the floor of the chest cavity?

      Ans. A large, muscular sheet called diaphragm forms the floor of the chest cavity.


      Q11. What are the end products of anaerobic respiration?

      Ans. The end products of anaerobic respiration are alcohol, carbon dioxide and energy.


      Q12. What is produced during anaerobic respiration in muscles that causes cramps?

      Ans. Lactic acid is produced during anaerobic respiration in muscles that causes cramps.


      Q13. What is cellular respiration?

      Ans. The process of breakdown of food in the cell with the release of energy is called cellular respiration.


      Q14. What is breathing rate?

      Ans. The number of times a person breathes in a minute is termed as the breathing rate.


      Q15. Why smoking should be avoided?

      Ans. Smoking damages lungs. Smoking is also linked to cancer. So, it must be avoided.


      Q16. What are spiracles?

      Ans. Insects have small openings on their body that allow them to breathe. These openings are called spiracles.

      Q17. Why we should eat regularly?

      Ans. We should eat regularly because food has stored energy, which is released during respiration.


      Q18. What is a stomata and what is its function?

      Ans. Leaves of the plants have tiny pores called stomata for exchange of oxygen and carbon dioxide.


      Q19. What is breathing?

      Ans. Breathing means taking in air rich in oxygen and giving out air rich in carbon dioxide with the help of respiratory organs.


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