10. RESPIRATION IN ORGANISMS
1. After finishing the race an athlete breath faster and deeper than usual because the demand for energy is high
in the muscles and to meet this demand more oxygen is required. Therefore, breathing rate increases to absorb
much required oxygen.
2. Similarities between aerobic respiration and aerobic respiration:
(a) Both are different modes of respiration.
(b) Energy is liberated in both the methods.
(c) Both take place at cellular level.
Dissimilarities between aerobic respiration and aerobic respiration:
S.N
Aerobic respiration
S.N.
Anaerobic respiration
1
Occurs in the presence of oxygen.
1
Occurs in the absence of oxygen.
2
Huge amount of energy is liberated.
2
Less amount of energy is liberated.
3
End products are water and carbon dioxide.
3
End products are lactic acid (in animals) or
alcohol (in plants and micro-organisms).
3. When we inhale unwanted particles they get trapped in the hair present in our nasal cavity. But if they get past
the hair they irritate the lining of the cavity, as a result of which we sneeze. Sneezing expels these foreign
particles from the inhaled air and a dust free, clean air enters our body.
4. Test tube A will have the highest concentration of CO2 because it contains a snail which is an organism
incapable of photosynthesis and due to respiration the concentration of CO2 will increase.
5. Tick the correct answer:
(a) In cockroaches, air enters the body through
(iii) spiracles
(b) During heavy exercise, we get cramps in the legs due to the accumulation of
(ii) lactic acid
(c) Normal range of breathing rate per minute in an average adult person at rest is:
(ii) 15-18
(d) During exhalation, the ribs
(ii) move downwards
6. Match the items in the column I with those in column II
Column I
Column II
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
7. Mark “T” if statement is true and “F” if it is false:
(i)
During heavy exercise the breathing rate of a person slows down. (F)
(ii)
Plants carry out photosynthesis only during the day and respiration only at night. (F)
(iii)
Frogs breathe through their skins as well as their lungs. (T)
(iv)
The fishes have lungs for respiration. (F)
(v)
The size of the chest cavity increases during inhalation. (T)
8. Complete the square puzzle yourself.
9. The mountaineers carry oxygen with them because:
(b) The amount of air available to a person is less than that available on the ground.