Respiration In Organisms, Class 7th Notes

THESE NOTES ARE PREPARED ACCORDING TO JKBOSE SYLLABI IN SIMPLIFIED AND CONCISE PATTERN

Exercises

1. Define cellular respiration.

Ans: Cellular respiration is the process of breakdown of food in the cells to release energy.

Cellular respiration is of two types:
Aerobic respiration.
Anaerobic respiration.

2. Why does an athlete breathe faster and deeper than usual after finishing the race?

Ans: An athelete breathes faster and deeper than usual after finishing the race so that more oxygen could reach his/her muscle cells.

During the race, lactic acid is produced in atheletes' muscles. The oxygen then breaks down lactic acid into carbon dioxide (CO2) and water (H2O).

3. List the similarities and differences between aerobic and anaerobic respiration.

Ans:
Similarities:

Both aerobic and anaerobic respiration gives energy to the body.

Both aerobic and anaerobic respiration uses glucose to release energy.

Differences:
Aerobic respiration takes place in presence of oxygen whereas anaerobic respiration takes place in absence of oxygen.

In aerobic respiration, Carbon dioxide is formed where as in anaerobic respiration, alcohol or lactic acid is formed.

4. Why do we often sneeze when we inhale a lot of dust-laden air?

Ans: The dust laden air irritates the inner lining of respiratory track. Hence, we sneeze to expel it out.

5. Take three test tubes. Fill ¾th 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?

Ans: Test tube A would have the highest concentration of CO2 as snail would release CO2 during respiration.

6. Tickmark the correct answer:

a. In cockroaches, air enters the body through:

(i)lungs (ii)gills (iii) spiracles (iv) skin

Ans: (iii) spiracles

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

Ans: (ii) lactic acid

c. 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

Ans: (ii)15-18

d. During exhalation, the ribs:

(i) move outwards (ii) move downwards
(iii) move upwards (iv) do not move at all

Ans: (ii) move downwards

7. Match the items in column I with those in column II :

Ans:

a. Yeast           :::   iii. Alcohol
b. Diaphragm :::   iv. Chest Cavity
c. Skin             :::     i.   Earthworm
d. Leaves        :::    v. Stomata
e. Fish             :::   ii. Gills
f. Frog             ::: vi. Lungs and Skin
g. Cockroach   ::: vii. Tracheae

8. Mark 'T' if the statement is true and 'F' if it is false:

i. During heavy exercise the breathing rate of a person slows down.   (T/F)
Ans: False

(ii) Plants carry out photosynthesis only during the day and respiration only at night.(T/F)
Ans: False

Explaination: Whereas Photosynthesis occurs only during day but respiration occurs during both day and night

(iii)Frogs breathe through their skin as well as their lungs. (T/F)
Ans: True

(iv) The fishes have lungs for respiration.(T/F)
Ans: False

(v)The size of the chest cavity increases during inhalation. (T/F)
Ans: True

9. 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.

i. The air tubes of insects
ii. Skeletal structure surrounding chest cavity
iii. Muscular floor of the chest cavity
iv. Tiny pores on the surface of the leaf
v. Small openings on the sides of the body of an insect
vi. The respiratory organs of human beings
vii. The openings through which we inhale
viii.Ananaerobic organism
ix. An organism with tracheal system

Ans:

Respiration In Organisms Class 7th crossword

i. The air tubes of insects: Trachea
ii. Skeletal structure surrounding chest cavity: Ribs
iii. Muscular floor of the chest cavity: Diaphragm
iv. Tiny pores on the surface of the leaf: Stomata
v. Small openings on the sides of the body of an insect: Spiracles
vi. The respiratory organs of human beings: Lungs
vii. The openings through which we inhale: Nostrils
viii.Ananaerobic organism: Yeast
ix. An organism with tracheal system: Ant

10. 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 air is higher than on the ground.
d. The pressure of air is higher than that on the ground.

Ans: b. The amount of air available to a person is less than that available on the ground.

11. Give two examples of each of the following:

(1) Animals that breathe through gills: Trout, Shark

(2) Animals that breathe through spiracles: Cockroach, Grasshopper

(3) Animals that breathe through skin: Frog, Earthworm

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