Free Respiration MCQs with Answers
446 Respiration MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The human respiratory system includes the air passages, lungs, alveoli and breathing muscles, while gaseous exchange explains how oxygen enters blood and carbon dioxide leaves it by diffusion. The effects of smoking include damage to cilia and alveoli, reduced gas exchange, chronic bronchitis, emphysema and increased risk of lung cancer.
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Read the Respiration notesFree MDCAT chapter notes with key terms446 questions · page 22 of 23
- A. Respiratory distress syndrome
- B. Emphysema
- C. Bronchitis
- D. Asthma
Explanation: The key feature of respiratory distress syndrome (RDS) is the insufficient production of surfactant in the lungs.Emphysema is a lung…
Correct answer: Respiratory distress syndrome- A. Inspiration is an active process
- B. Expiration is a passive process
- C. Inspiration is a passive process
- D. Both expiration and inspiration are passive processes
Explanation: Inspiration is an active process because it involves the contraction of the diaphragm and intercostal muscles, which results in the…
Correct answer: Inspiration is an active process- A. Trachea
- B. Bronchi
- C. Bronchioles
- D. Alveoli
Explanation: Bronchi are larger airway passages in the respiratory system, and they are primarily lined with cartilage for structural support.
Correct answer: Alveoli- A. 5-6 liter.
- B. 8-9 liter
- C. 10-11 liter
- D. 12-13 liter
Explanation: The normal lung capacity of an average adult human is about 5 to 6 liters.
Correct answer: 5-6 liter.- A. Sodium
- B. Potassium
- C. Bicarbonate
- D. Chloride
Explanation: The majority of carbon dioxide is transported as bicarbonate ions. This is because erythrocytes have a high activity of carbonic…
Correct answer: Bicarbonate- A. 2ml
- B. 3ml
- C. 4ml
- D. 5ml
Explanation: 6 mL of oxygen is delivered, at tissue level in normal conditions so option D is correct
Correct answer: 5ml- A. 10-30m
- B. 30-60m
- C. 70-90m
- D. 90-110m
Explanation: The alveoli form the gas exchange surface in the lungs, with about 700 million alveoli contributing to a total surface area of 70-90m2.
Correct answer: 70-90m- A. Cuboidal epithelium
- B. Squamous epithelium
- C. Columnar epithelium
- D. Transitional epithelium
Explanation: The alveoli, which are tiny air sacs in the lungs, are lined by a type of epithelium called squamous epithelium.
Correct answer: Squamous epithelium- A. Alveoli form the gas exchange surface
- B. The wall of each alveolus is 0.1 cm thick
- C. Alveoli has a dense network of capillaries
- D. Collagen and elastin present in alveoli allow it to expand and recoil easily during breathing
Explanation: Option B regarding alveoli is not correct.The walls of alveoli are extremely thin, only about 0.0002 cm thick.
Correct answer: The wall of each alveolus is 0.1 cm thick- A. Chest wall is raised and diaghram is lowered
- B. Chest wall is raised and diaghram is also raised
- C. Chest wall is lowered and diaghram is raised
- D. Chest wall is lowered and diaghram is also lowered
Explanation: Ok we will go through inspiration and expiration on a conceptual basis During inspiration, air moves in the lungs, so atmospheric pressure…
Correct answer: Chest wall is raised and diaghram is lowered- A. Fibrous
- B. Hyaline
- C. Elastic
- D. Neurotic
Explanation: Hyaline cartilage is found at the ends of long bones and in the nose at the larynx and trachea.
Correct answer: Hyaline- A. Digestive
- B. Circulatory
- C. Respiratory
- D. Excretory
Explanation: Instead of nostrils, grasshoppers breathe through openings in the thorax and abdomen called spiracles.
Correct answer: Respiratory- A. Fishes
- B. Amphibians
- C. Birds
- D. Mammals
Explanation: Alveoli, small air sacs in the lungs where gas exchange occurs, are present in fishes.
Correct answer: Fishes- A. Birds
- B. Crocodiles
- C. Fishes
- D. Toads
Explanation: Correct Answer: BirdsThe presence of a diaphragm in birds allows for effective respiration by assisting in lung function.
Correct answer: Birds- A. Birds
- B. Crocodiles
- C. Fishes
- D. Toads
Explanation: Mammals are characterized by a well-developed diaphragm that separates the thoracic chamber from the abdominal cavity.
Correct answer: Crocodiles- A. The cardiac center
- B. Ventilation center
- C. Pons
- D. Carotid sinus
Explanation: The rhythmicity of respiration is primarily maintained by the respiratory centers located in the pons region of the brainstem.
Correct answer: Pons- A. 44 times/minute
- B. 40 times/minute
- C. 25 times/minute
- D. 20 times/minute
Explanation: The breathing rate decreases with age. Some average breathing rates are given below: 2-5 years= 25-30 breaths/min 5-12 years= 20 to 25…
Correct answer: 25 times/minute- A. Trachea
- B. Bronchus
- C. Bronchioles
- D. Tracheoles
Explanation: The correct answer is Bronchioles. Bronchioles do not contain cartilage, unlike the trachea and bronchi, which have cartilage to maintain…
Correct answer: Bronchioles- A. 19.4 ml
- B. 19.6 ml
- C. 20 ml
- D. 21 ml
Explanation: In 100 ml of blood, there is about 15 g of hemoglobin, which can bind approximately 20.1 ml of oxygen.
Correct answer: 20 ml- A. 77%
- B. 90%
- C. 87%
- D. 97%
Explanation: Red blood cells (also known as erythrocytes) contain a protein called hemoglobin, which carries oxygen from the lungs to all parts of the…
Correct answer: 97%