BIOLOGY [2 Mark Question Answer]

1. Ribs muscles—During inhalation, the ribs muscles contract and push the ribs upward and outward. During exhalation, these relax and cause the ribs to return to the original position.
2. Diaphragm: During inhalation, it becomes flattened while during exhalation it relaxes and moves up and back into convex (dome) shape.

1. It is a physical process.
2. Air containing oxygen is taken into the lungs and air loaded with carbon dioxide is given out.
3. Lungs are mainly involved.

Respiration

1. It is a catabolic process
2. Oxygen taken in is used in oxidizing glucose and energy is released.
3. It occurs in tissues and cells of the body.

1. The two branching tubes of the trachea is called bronchi.
2. There are two bronchi
3. The walls of bronchi are not richly supplied with blood capillaries.

Alveoli

1. The outgrowths of microscopic air sacs are called alveoli.
2. There are millions of alveolar sacs.
3. The walls of the bronchioles are richly supplied with blood capillaries.

1. It is a complex biochemical process which involves enzymes.
2. It involves oxidation of glucose into CO2, water and energy.
3. Energy is released and stored in the form of ATP.
4. It takes place inside the cell.

Breathing

1. It is a mechanical process without the involvement of enzymes.
2. It involves only the exchange of oxygen and CO2.
3. No energy is released.
4. It takes place outside the cell.