Biology ICSE Class 7 Important Questions Chapter 7 Respiration in Animals and Plants
Extra Questions
Question 1.
Why is it better to breathe through your nose than your mouth ?
Answer:
It is better to breathe through our nose than our mouth because our nasal cavity is lined by hair. The air we breathe in contains fine dust particles. These particles get trapped in the hair in the nasal cavity and are thereby prevented front reaching the lungs. The inside of the nose is also covered by a sticky fluid called mucus. Dust and germs stick to the mucus and thus, the air taken in is cleaned. The air is also warmed up by blood vessels present in the nasal cavity.
Question 2.
Where does the process of cellular respiration take place ?
Answer;
Partially in the cytoplasm and partially in the mitochondria.
Question 3.
Write the equation showing the process of anaerobic respiration.
Answer:
Question 4.
What is epiglottis ?
Answer:
A flap-like tissue behind the tongue called epiglottis covers the trachea when we swallow food and prevents food from entering the wind pipe while eating.
Question 5.
Write a brief note on structure of lungs.
Answer:
A pair of lungs are the main respiratory organs in humans. Each lung is a spongy bag-like structure covered by a pleural membrane. In between the two pleural membranes, there is a fluid called pleural fluid which keeps the surface of the lungs moist for easy gas diffusion. The lungs are protected by the rib cage. Below the lungs is a muscular sheet called diaphragm.
Question 6.
Name two stages involved in respiration in humans.
Answer:
Breathing and cellular respiration.
Question 7.
Name the main respiratory organ of –
(i) insects
(ii) fish
(iii) humans
(iv) amphibians.
Answer:
(i) Spiracles and tracheae
(ii) Gills
(iii) Lungs
(iv) Moist skin, mouth cavity and lungs.
Question 8.
Fill in the blanks.
(i) ………….. (and not digestion) releases usuable energy from food.
Answer:
Respiration (and not digestion) releases usuable energy from food.
(ii) Average resting respiratory rate for adults is ………… breaths per minute.
Answer:
Average resting respiratory rate for adults is 12 to 20 breaths per minute.
(iii) Breathing in air is called and breathing out air is called ………….
Answer:
Breathing in air is called inhalation and breathing out air is called exhalation.
(iv) In the process of aerobic respiration, …………. molecules of ATP are released.
Answer:
In the process of aerobic respiration, 38 molecules of ATP are released.
(v) The alveolar sacs are surrounded by a network of ………….
Answer:
The alveolar sacs are surrounded by a network of blood capillaries.
(vi) Trachea branches into two tubes called …………. in humans.
Answer:
Trachea branches into two tubes called bronchi in humans.
Question 9.
What happens to lime water when exhaled air is passed through it ?
Answer:
When the exhaled air is passed through lime water it turns milky. The milkiness of lime water shows that the exhaled air has carbon dioxide in it i.e. Carbondioxide is produced during respiration.
ICSE Class 7 Biology Important Questions