Unit 1B: Breathing and Exchange of Gases — Online MCQ Test
ZOOLOGY · CLASS 12 INTERMEDIATE 2 YEAR · Telangana State Board
Practice Unit 1B: Breathing and Exchange of Gases with a free chapter-wise online MCQ test.
This chapter covers: This chapter details human respiratory system structure mechanics of breathing pulmonary volumes capacities gas exchange across alveoli hemoglobin oxygen transport and respiratory....
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Unit 1B: Breathing and Exchange of Gases — Important Questions & Answers
Which structure is the primary site of gas exchange in the human respiratory system?
- A. Trachea
- B. Alveoli
- C. Bronchi
- D. Larynx
Answer: B. Alveoli
Alveoli have thin walls and a rich capillary network, making them ideal for exchange of oxygen and carbon dioxide.
Alveoli have thin walls and a rich capillary network, making them ideal for exchange of oxygen and carbon dioxide.
The normal respiratory rate of a healthy adult at rest is approximately:
- A. 6–8 breaths per minute
- B. 12–16 breaths per minute
- C. 20–25 breaths per minute
- D. 30–35 breaths per minute
Answer: B. 12–16 breaths per minute
A healthy adult normally breathes about 12 to 16 times per minute at rest.
A healthy adult normally breathes about 12 to 16 times per minute at rest.
During inspiration, the diaphragm:
- A. Moves upward and becomes dome-shaped
- B. Moves downward and flattens
- C. Remains stationary
- D. Contracts and moves the ribs downward
Answer: B. Moves downward and flattens
When the diaphragm contracts, it flattens and increases thoracic cavity volume, helping air enter the lungs.
When the diaphragm contracts, it flattens and increases thoracic cavity volume, helping air enter the lungs.
Which of the following statements about carbon monoxide poisoning is correct?
- A. CO binds loosely to haemoglobin and is easily removed
- B. CO has a much higher affinity for haemoglobin than oxygen
- C. CO increases oxygen carrying capacity of blood
- D. CO is converted into oxygen inside RBCs
Answer: B. CO has a much higher affinity for haemoglobin than oxygen
Carbon monoxide binds haemoglobin very strongly, reducing the blood’s oxygen-carrying capacity.
Carbon monoxide binds haemoglobin very strongly, reducing the blood’s oxygen-carrying capacity.
Which of the following is the correct pair of respiratory disorder and its cause?
- A. Asthma — irreversible destruction of alveoli
- B. Pneumonia — inflammation of alveoli due to infection
- C. Occupational respiratory disorder — deficiency of haemoglobin
- D. Asphyxia — excessive production of surfactant
Answer: B. Pneumonia — inflammation of alveoli due to infection
Pneumonia is an infection that inflames the alveoli and can fill them with fluid, impairing gas exchange.
Pneumonia is an infection that inflames the alveoli and can fill them with fluid, impairing gas exchange.