I. Conceptual understanding:
Q. What is Respiration?
Answer: Respiration is the process by which food is broken down for release of energy.
Q. What is the origin of the word "Respiration"? What is the meaning of the word?
Answer: Respiration originates from the word "respire" which means "to breath" "Respire" is a Latin word.
Q. Can you draw a flow chart of the pathway of air in our body?
Answer: Nostrils   nasal cavity  pharynx  larynx  trachea  bronchi  bronchioles  lungs  alveoli.
Q. What is it that controls movement of air and food in the throat?
Answer: A flap like muscular valve called 'Epiglottis' controls movement of air and food towards their respective passages.
Q. Where does gaseous exchange take place?
Answer: Gaseous exchange takes place in alveoli. The blood capillaries in the alveoli take up oxygen and expel carbon dioxide.
Q. What is the nature of the lungs?
Answer: They are spongy and elastic in nature.
Q. What is diaphragm?
Answer: Diaphragm is a muscular tissue present at the floor of the chest cavity.
Q. Define inspiration and expiration.
Answer:
Inspiration: The rushing of the air from outside into the lungs when the volume of the chest cavity is increased when the internal pressure decreases is called inspiration.
Expiration: The expelling of the air from inside into the atmosphere when the chest wall is lowered and moves inward and the diaphragm relaxes and assumes its dome shape, increasing the pressure on the lungs that contracts the elastic tissues of the lungs to expel air out.
Q. What are the two stages in which glucose is oxidized?
Answer: Glucose is oxidized in two stages.
Stage 1: Glucose is converted into two molecules of pyruvic acid.
Stage 2: Pyruvic acid is oxidized to carbon dioxide and water. this happens only in the presence of oxygen. Lot of energy is released.
If there is inadequate oxygen or no oxygen, pyruvic acid is converted into either ethanol or lactic acid and very little amount of energy is released.
Q. Where does respiration take place in plants?
Answer: Respiration occurs in cytoplasm and mitochondria in plants.
Q. Where does gaseous exchange take place in plants?
Answer: Gaseous exchange takes place in stomata of leaves in plants.
Q. Write the differences between photosynthesis and Respiration.
Answer:
Q. Write equations for photosynthesis and Respiration
Answer:
Equations:
Photosynthesis:
      
Respiration:
         C6H12O6 + 6 O2  6 CO2 + 6 H2O  + 686 K. cal
Q. Write the significance of Respiration.
Answer: Respiration requires carbohydrates and oxygen to undergo the process.
　 As the complex molecules are broken down in this process, we can say that it decreases the weight of the organism.
　 Both plants and animals require respiration because it is the process in which food is converted into energy in the form of ATP, which is used for many processes within all organisms.
　　 We can say that both reactions transform energy in one way or another - either storing it or releasing it.

Oxygen produced during photosynthesis replenishes the oxygen that was used up by the living organisms during respiration.
　　 The cycle of photosynthesis and respiration maintains the balance of carbon dioxide and oxygen on earth.
Q. Can you describe the organs of respiration in different animals in a table?
Answer: 

Q. How does respiration in amoeba occur by diffusion?
Answer: 1. Amoeba is an aquatic organism.
       2. Oxygen is present both in cytoplasm and also in the surrounding water.
 3. Due to respiration, oxygen present in the cytoplasm when compared to surrounding water.
       4. This lowers the amount of oxygen present in the cytoplasm when compared to surrounding water.
       5. When this happens, oxygen present in the water diffuses into cytoplasm.
       6. Respiration is a continuous process, oxygen continuously diffuses from surrounding water into the animals.
Q. Write an account on the lungs of man?
Answer: 1. A pair of lungs are present in the chest cavity one on either side of the heart.
       2. Lungs are spongy, elastic and are enclosed by two membranes called 'Pleura'.
       3. Space between the two membranes of the pleura is filled with fluid.
       4. Pleura protects the lungs from injury.
       5. Right lung is large than the left lung.
       6. Right lung is made of three lobes while the left lung has only two lobes.
       7. As mentioned earlier, the lung has several thousands of alveoli which are supplied with blood capillaries.
8. The pulmonary artery brings de-oxygenated blood from heart to lungs.
       9. After entering the lungs, the artery divides into several arteioles and capillaries and supplies de-oxygenated blood to alveoli.
       10. Gaseous exchange occurs in the alveoli.
       11. The oxygenated blood is carried from the lungs to heart by the pulmonary vein.
II. Asking questions and making hypothesis:
Q. See this diagram. Prepare 5 questions about it. 
      
Answer: 
       1. What are these organs?
       2. Do they aid in respiration?
       3. Why are the vessels in these organs branched?
4. How do they help in any activity?
       5. I can tell how air enters inside by the help of arrows shown. But, how does the air go out?
Q. Prepare some questions on the doubts that arose in your mind while listening to the lesson "Respiration."
Answer: 
       1. What will happen if the respiratory tract is not moist?
       2. Are both lungs similar in size?
       3. Why alveoli are so small and uncountable in number?
       4. What is the gas that we give out in exhalation?
       5. What is the gas that we breath?
Q. See the following diagram. Prepare questions on it.