What is Respiration Multiple Choice Questions (MCQ) PDF Download

MCQ 1: Air pressure in thorax increases in

1. anaerobic respiration
2. inspiration
3. expiration
4. digestion

MCQ 2: Blood entering the lungs contain very

1. little oxygen (O₂) only
2. high carbon dioxide (CO₂) only
3. low carbon dioxide (CO₂)
4. little oxygen (O₂) and high carbon dioxide (CO₂)

MCQ 3: In expiration in process of respiration

1. the diaphragm relaxes and arches upwards
2. air enters the lungs
3. ribs move upwards
4. sternum moves up and away from backbone

MCQ 4: Stimulus for breathing is

1. lack of oxygen in blood
2. excess of carbon dioxide in blood
3. contraction of alveoli
4. diaphragm movements

MCQ 5: In anaerobic respiration (without O₂) in mammals, the wastes are

1. water
2. ethanol
3. lactic acid
4. carbon dioxide