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.
Last updated
Read the Respiration notesFree MDCAT chapter notes with key terms446 questions · page 21 of 23
- A. Chemical process
- B. Biochemical process
- C. Mechanical process
- D. Both Option B and C are correct
Explanation: Respiration is both mechanical and biochemical process
Correct answer: Both Option B and C are correct- A. Carboxyhemoglobin
- B. Plasma proteins
- C. Bicarbonate ions
- D. In dissolved form
Explanation: 70% of carbon dioxide is transported in the blood as bicarbonate ions, 23% as carboxyhemoglobin and 7% in water of plasma.
Correct answer: Bicarbonate ions- A. Glottis
- B. Voice box
- C. Epiglottis
- D. Vocal cords
Explanation: The voice box or larynx is located at the upper end of the trachea. It is a hollow chamber with cartilaginous walls and contains a pair of…
Correct answer: Voice box- A. Emphysema
- B. Asthma
- C. Pneumonia
- D. Bronchitis
Explanation: Pneumonia is a disease of the upper respiratory tract in which Chills, sputum production and fever is observed.
Correct answer: Pneumonia- A. Bronchi
- B. Bronchioles
- C. Windpipe
- D. Larynx
Explanation: Air from pharynx passes to larynx, which is called voice box.
Correct answer: Larynx- A. Glottis
- B. Epiglottis
- C. Larynx
- D. Vocal cords
Explanation: Epiglottis guards the opening of the larynx and it is flap-like in shape.
Correct answer: Epiglottis- A. 3.5 litres
- B. 2.5 litres
- C. 5.5 litres
- D. 8 litres
Explanation: The total lung capacity means the maximum amount of gas that a lung can hold. It is approximately 5-6 liters.
Correct answer: 5.5 litres- A. Lungs pull air inside
- B. Passive transport of air takes place
- C. Passive expansion of air takes place
- D. Air is pushed inside
Explanation: Lungs pull air inside: This option is correct. During inspiration, the expansion of the thoracic cavity occurs passively due to the…
Correct answer: Lungs pull air inside- A. Increases many folds
- B. Decreases
- C. Remains constant
- D. Is doubled
Explanation: Since CO2 reacts with water to form carbonic acid, an increase in CO2 results in a decrease in blood pH resulting in haemoglobin proteins…
Correct answer: Decreases- A. Air sac
- B. Trachea
- C. Larynx
- D. Bronchioles
Explanation: Option [a] Air sacs, and alveoli are present at the end of bronchioles in lungs where lungs and blood exchange oxygen and carbon dioxide…
Correct answer: Air sac- A. It must be permeable
- B. It must be thick for low diffusion
- C. It should be non-vascularized
- D. It should have low ventilation mechanism
Explanation: Respiratory surfaces, such as the alveoli in the lungs, must be permeable to allow the exchange of gases (oxygen and carbon dioxide)…
Correct answer: It must be permeable- A. Photorespiration
- B. Ventilation
- C. Gaseous transport
- D. Respiration
Explanation: Ventilation is the process of moving air in and out of the respiratory system, allowing for the exchange of gases (such as oxygen and…
Correct answer: Ventilation- A. Carbonate
- B. Bicarbonate
- C. Tricarbonate
- D. Carbonic anhydrase
Explanation: About 70 percent of CO2 is transported in the form of Bicarbonate ions.
Correct answer: Bicarbonate- A. 5 ml
- B. 50 ml
- C. 500 ml
- D. 5000 ml
Explanation: The total lung capacity is approximately 5 L. Of this, 1.5 L, the residual volume, remains at the end of forced expiration.
Correct answer: 5000 ml- A. Bicarbonate
- B. COz
- C. Carboxyhemoglobin
- D. Blood plasma protein
Explanation: Explanation:The majority of carbon dioxide molecules are carried as part of the bicarbonate buffer system.This option is not correct.
Correct answer: Bicarbonate416. Which one of following factors is directly proportional to oxygen carrying capacity of haemoglobin:
- A. Carbon dioxide
- B. Temperature
- C. pH
- D. Light
Explanation: Option [A] the greater the carbon dioxide the lesser the capacity to carry oxygen, as Co2 increases more H+ ions are produced in…
Correct answer: pH- A. Contraction of lungs
- B. Contraction of intercostal membrane
- C. Relaxation of intercostal and diaphragm muscles
- D. Contraction of diaphragm muscles
Explanation: Option [a] Lungs do not contractOption[b] Internal intercostal muscles contractOption [c] During expiration External intercostal muscles…
Correct answer: Relaxation of intercostal and diaphragm muscles- A. 6.7 litres
- B. 2.5 litres
- C. 7 litres
- D. 5-6 litres
Explanation: In an adult human being when the lungs are fully inflated the total inside capacity of lungs is about 5-6 litres.
Correct answer: 5-6 litres- A. Amino group of haemoglobin
- B. Iron is part of haemoglobin
- C. heme portion of haemoglobin
- D. Plasma proteins
Explanation: Carbaminohemoglobin is a stable complex of carbon dioxide and hemoglobin that forms in red blood cells upon contact with carbon dioxide.
Correct answer: Amino group of haemoglobin- A. 1.2 cm
- B. 1 cm
- C. 1 mm
- D. 1.2 mm
Explanation: When the smaller bronchi attain a diameter of one mm or less, then they are called bronchioles.
Correct answer: 1 mm