VII Biology Ch. respiration in plants and animals Solution of Extra score questions

VII Biology Ch. respiration in plants and animals For scoring students

1.Q. why we breathe faster after a hard work?

Ans: We breathe faster after a hard work for more energy that is fulfilled by fast respiration.

2.Q. What are difference between breathing and respiration?

Ans: Differences between breathing and respiration are:

Breathing

1. It is a physical process because only the air moves from one place to another. 2. During this, energy is not released. 3. It involves breathing organs.

Respiration

1. It is a chemical process because the food undergoes chemical changes. 2. During this, energy is released. 3. It takes place in living cells.

3.Q. Distinguish between respirations from photosynthesis?

Ans: Respiration

1. It takes place throughout day and night. 2. All living organisms do it. 3. Food is consumed. 4. During this process oxygen is taken in and carbon dioxide is given out.

Photosynthesis

1. It takes place during day time.  2. Only green plants do it. 3. Food is synthesized. 4. During this process carbon dioxide is taken in and oxygen is given out

4.Q. what is the difference between the burning of food in cells and burning of wood?

Ans: Respiration

1. It takes place in living cells. 2. Heat energy is liberated. 3. Energy is released step by step in small quantity.

Burning of wood

1. It takes place outside. 2. Heat and light energy are liberated. 3. Energy is released all of a sudden in large quantity.

5.Q. How diaphragms help in breathing?

Ans: As we breathe in, the diaphragm moves down and ribs move up or expands. This movement increases space in our chest cavity.  Then the air rich in oxygen rushes into our lungs from outside. As we breathe out, the diaphragm moves up to its original place and ribs move down. This reduces the size of the chest cavity and air is pushed out of the lungs through bronchi, trachea and nose.

6. Q. why we sneeze?

Ans: We sneeze when dust enter and irritate the nasal cavity. A sneeze expels unwanted harmful particles from the nasal cavity.

7.Q. Why we get muscle cramps after heavy exercise?

Ans:  The anaerobic respiration takes place in the muscle cells during exercise to fulfill the excess demand of energy and produces lactic acid  causes muscle cramps.

8.How much air lung hold of a normal people?

Ans: 3500 ml

9. Q.How many alveoli are in our lungs?

Ans: About 300 millions

10. What is lungs

Ans: Lungs is spongy, pink and elastic respiratory organ.

11. What is the function of epiglottis

Ans: Epiglottis prevents food to enter in wind pipe and work as guars between larynx and pharynx.

Q.12. Why it is advised to breathe through nose not through mouth?

Ans: In nose there are mucus and nose hair that filter air before entering in trachea .so it is advised to breadth through nose only.

Q.13. Why do plant do not have respiratory system?

Ans: Plant respiration is limited by the process of diffusion and nutrients and gases diffuse directly  thus have no need of special organ and organ system.

Q. 14.How fishes breathe under water?

Ans: Fishes use gills to breathe oxygen dissolved in water .Gills are well supplied with blood vessels for exchange of gases..

Q. 15.Aquatic plants do not have stomata. So, how does exchange of gasses take place in them?

Ans: In submerged plants the exchange of gases take place through body surface while in floating plants the stomata are present on the upper surface of leaf.

Q. 16.Why do we yawn when we are sleepy?

Ans: Our body induce yawning to drawn in more oxygen or remove a build-up of carbon dioxide. we yawn to gather a large amount of oxygen for our brain, to help it function faster

Q.17. What do you mean by vital capacity? What is the vital capacity of a normal human being?

Ans: Maximum amount of air a person can breathe in/out after a forceful expiration/inspiration is called vital capacity .In men its value is approximately 4.8 litres while in females, it is approximately 3.5 litres.