Question

B. Short-Answer Questions
1. Differentiate between external and internal (or
cellular) respiration.
2. What are the steps involved in the formation of
lactic acid from glucose?
3. Why is the rate of breathing faster in aquatic
organisms than in terrestrial organisms?
4. Differentiate between respiration in plants and
animals.
5. In what forms are oxygen and carbon dioxide
transported in the blood?
6. How are oxygen and carbon dioxide transported in
human beings? How are lungs designed to
maximise the area for exchange of gases? [CBSE]
7. Give reasons for the following.
(CBSE)
(a) The glottis is guarded by the epiglottis.
(b) The alveoli in lungs are covered with blood
capillaries.
(c) The wall of trachea is supported by cartilage
rings.​

Answer 1

The two main gases exchanged are oxygen and carbon-dioxide. Oxygen is absorbed by the blood capillaries from the lungs alveoli by diffusion while carbon-dioxide is absorbed by the lungs alveoli from blood capillaries by diffusion. ... Oxygen is transported from lungs to the body cells in the form of oxy-hemoglobin.