Gujarat Board GSEB Textbook Solutions Class 7 Science Chapter 10 Respiration in Organisms Textbook Questions and Answers, Notes Pdf.

Gujarat Board Textbook Solutions Class 7 Science Chapter 10 Respiration in Organisms

Gujarat Board Class 7 Science Respiration in Organisms Textbook Questions and Answers

Question 1.
Why does an athlete breathe faster and deeper than usual after finishing the race?
Answer:
The athlete has to run fast during the race. The body needs more energy which increases the demand for oxygen to breakdown food. So, the athlete has to breathe faster and deeper to inhale more oxygen.

Question 2.
List the similarities and differences between aerobic and anaerobic respiration.
Answer:
Differences:
Aerobic Respiration:

• It occurs in the presence of oxygen.
• A large amount of energy is released.
• Food molecules are broken down into water and carbon dioxide.

Anaerobic Respiration:

• It occurs in the absence of oxygen.
• A small amount of energy is released.
• Food molecules are broken down into ethyl alcohol and carbon dioxide.
• Similarities: Both aerobic and anaerobic respiration produces energy and gives out carbon dioxide.

Question 3.
Why do we often sneeze when we inhale a lot of dust-laden air?
Answer:
Sometimes dust particles, pollen etc. pass nasal hair and irritate the lining of the nasal cavity. Then we sneeze as we want to get rid of the unwanted particles like dust, pollen etc. from our body. It allows only clean and dust-free air to enter our bodies.

Question 4.
Take three test-tubes. Fill 3/4th of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B, and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO₂?
Answer:
There will be the highest concentration of CO₂ in test-tube A.

Question 5.
Tick the correct answer:
(a) In cockroaches, air enters the body through
(i) lungs
(ii) gills
(iii) spiracles
(iv) skin

(b) During heavy exercise, we get cramps in the legs due to the accumulation of
(i) carbon dioxide
(ii) lactic acid
(iii) alcohol
(iv) water

(c) The normal range of breathing rate per minute in an average adult person at rest is:
(i) 9-12
(ii) 15-18
(iii) 21-24
(iv) 30-33

(d) During exhalation, the ribs
(i) move outwards
(ii) move downwards
(iii) move upwards
(iv) do not move at all
Answer:
(a) (iii) Spiracles
(b) (ii) Lactic acid
(c) (ii) 15-18
(d) (ii) move downwards

Question 6.
Match the items in Column I with those in Column II:

Answer:

Question 7.
Mark ‘T’ if the statement is true and ‘F’ if it is false:

1. During heavy exercise, the breathing rate of a person slows down. (T/F)
2. Plants carry out photosynthesis only during the day and respiration only at night. (T/F)
3. Frogs breathe through their skins as well as their lungs. (T/F)
4. The fishes have lungs for respiration. (T/F)
5. The size of the chest cavity increases during inhalation. (T/F)

Answer:

1. False
2. False
3. True
4. True
5. True

Question 8.
Given below is a square of letters in which are hidden different words related to respiration in organisms. These words may be present in any direction upwards, downwards, or along the diagonals. Find the words for your respiratory system. Clues about those words are given below the square.

1. The air tubes of insects
2. Skeletal structures surrounding the chest cavity
3. The muscular floor of the chest cavity
4. Tiny pores on the surface of the leaf
5. Small openings on the sides of the body of an insect
6. The respiratory organs of human beings
7. The openings through which we inhale
8. An anaerobic organism
9. An organism with a tracheal system

Answer:

1. Trachea
2. Ribs
3. Diaphragm
4. Stomata
5. Spiracles
6. Lungs
7. Nostrils
8. Yeast
9. Ant

Question 9.
The mountaineers carry oxygen with them because:
(a) At an altitude of more than 5 km, there is no air.
(b) The amount of air available to a person is less than that available on the ground.
(c) The temperature of the air is higher than that on the ground.
(d) The pressure of air is higher than that on the ground.
Answer:
(b) The amount of air available to a person is less than that available on the ground.

Extended Learning Activities And Projects

Question 1.
Observe fish in an aquarium. You will find flap-like structures on both sides of their heads. These are flaps that cover the gills. These flaps open and close alternately. On the basis of these observations, explain the process of respiration in the fish.
Answer:
Gills are the respiratory organs of the fish. There are two gills, one on either side of the head. Gills are projections of the skin that are well supplied with blood vessels for the exchange of gases. In some fishes, each gill is covered with a flap that opens and closes alternately. Their opening and closing is related to the opening and closing of the mouth.

When the mouth of the fish opens, it engulfs water which passes over the gill. During this period exchange of gases takes place in the gills. In this period, the gill flap (called operculum) remains closed. After the exchange of gases, the gill flap opens and the water is pushed out.

Question 2.
Visit a local doctor. Learn about the harmful effects of smoking. You can also collect material on this topic from other sources. You can seek help from your teacher or parents. Find out the percentage of people of your area who smoke. If you have a smoker in your family, confront him with the material that you have collected.
Answer:
Due to smoking, the smoke particles get deposited on the respiration surface affecting the absorption of oxygen and the release of carbon dioxide from the body. Moreover, the nicotine present in tobacco smoke causes constriction of blood vessels and irritation of the windpipe. Thus, smoke increased the concentration of carbon dioxide, and constant irritation may cause T.B., bronchitis, and lung cancer.

Question 3.
Visit a doctor. Find out about artificial respiration. Ask the doctor:
(a) When does a person need artificial respiration?
(b) Does the person need to be kept on artificial respiration temporarily or permanently?
(c) From where can the person get a supply of oxygen for artificial respiration?
Answer:
(a) When there is an insufficient supply of oxygen due to lung troubles, heart troubles or drowning, etc., the patient needs an artificial supply of oxygen.
(b) Artificial respiration is the arrangement to provide the exchange of gases (oxygen and CO₂) to revive organs of the patient. It is not a permanent solution. However, some patients may be kept on artificial respiration to survive but they are not able to work or to do other social activities.
(c) The patient is supplied with an oxygen cylinder having compressed oxygen gas stored in it.

Question 4.
Measure the breathing rate of the members of your family and some of your friends. Investigate:
(a) If the breathing rate of children is different from that of adults.
(b) If the breathing rate of males is different from that of females.
If there is a difference in any of these cases, try to find the reason.
Answer:
Do it yourself.
(a) Yes, the breathing rate of children is always more than adults because they are more active and require more oxygen for their metabolic activities.
(b) Yes, the breathing rate of females is usually more than males.