respiration

Question 1

define respiration.

Answer 1

the process of intake of oxygen and its usage to break down glucose to produce energy.

Question 2

pathway of external respiration.

Answer 2

oxygen-rich air from atmosphere —> nasal cavities —> pharynx —> trachea —> bronchi —> bronchioles —> alveoli —> oxygen and carbon dioxide exchange at alveoli —> bronchioles —> bronchi —> trachea —> pharynx —> nasal cavities —> carbon dioxide rich air to environment

Question 3

differentiate between external and internal respiration.

Answer 3

1. external / breathing
   a) physical process
   b) no energy is produced
2. internal / cellular
   a) biochemical process
   b) energy is produced

Question 4

role of diaphragm in respiration.

Answer 4

1. diaphragm is situated below the lungs.
2. when it moves down it creates a low pressure which causes air outside to rush into the lungs.
3. when it moves upward, it forces the air in the lungs outside the body again.

Question 5

why do lungs always have a residual volume of air?

Answer 5

so that there is sufficient time for oxygen to be absorbed and for carbon dioxide to be released.

Question 6

why is rate of respiration faster in aquatic animals than in terrestrial animals?

Answer 6

aquatic animals take in oxygen dissolved in water which is much less than oxygen content in air.