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 17 of 23
- A. More dome like
- B. Less dome like
- C. Less flat
- D. Convex
Explanation: When the muscles of the diaphragm contract, it becomes less domed and more flattened.
Correct answer: Less dome like- A. Bright red oxyhemoglobin
- B. Purple red oxyhemoglobin
- C. Bright red hemoglobin
- D. Purple red hemoglobin
Explanation: Hemoglobin readily combines with oxygen to form "oxyhemoglobin." Oxyhemoglobin is the complex that is formed when oxygen molecules bind to…
Correct answer: Bright red oxyhemoglobin- A. Carboxylase
- B. Oxygenase
- C. Anhydrase
- D. Deoxygenase
Explanation: The enzyme that is involved in the dissociation of oxygen from hemoglobin is called "carbonic anhydrase." This enzyme catalyzes the…
Correct answer: Anhydrase- A. Asthma
- B. Respiratory distress syndrome
- C. Emphysema
- D. Sinusitis
Explanation: Deficiency of surfactant in infants can lead to a condition called "Respiratory Distress Syndrome" (RDS), also known as "Hyaline Membrane…
Correct answer: Respiratory distress syndrome- A. Air sacs
- B. Bronchioles
- C. Alveoli
- D. Bronchi
Explanation: The functional unit of the lungs is called the "alveolus" (plural: alveoli).
Correct answer: Air sacs- A. Nostril
- B. Glottis
- C. Nares
- D. Epiglottis
Explanation: The opening of the larynx is called the "glottis." The glottis is the space between the vocal cords, and it plays a crucial role in…
Correct answer: Glottis- A. Nostrils
- B. Pharynx
- C. Nasal cavities
- D. Nose
Explanation: Nose has two openings called nostrils. Nostrils have fine hair to trap dust particles present in the air and stops them from entering our…
Correct answer: Nostrils- A. Two passageways
- B. Three passageways
- C. Four passageways
- D. Five passageways
Explanation: To summarize, the correct answer is b) Three passage ways, as in each cavity there are three regions; nasal vestibule, respiratory region…
Correct answer: Three passageways- A. Its red colour
- B. Presence of iron
- C. Its ability to combine reversibly with oxygen
- D. Presence of basic protein globin
Explanation: The correct answer is c) Its ability to combine reversibly with oxygen.
Correct answer: Its ability to combine reversibly with oxygen- A. Directly proportional to CO2 concentration
- B. Indirectly proportional to CO2 concentration
- C. Inversely proportional to CO2 concentration
- D. Independent of CO2 concentration
Explanation: The correct answer is d) Independent of CO2 Concentration. Oxygen binding to hemoglobin is influenced by factors like partial pressure of…
Correct answer: Inversely proportional to CO2 concentration- A. pH of blood falls
- B. pH of blood rises
- C. CO2 concentration in blood falls
- D. Free fatty acid concentration in blood falls
Explanation: "The explanation for this question will be added soon!".
Correct answer: pH of blood falls- A. One
- B. Two
- C. Three
- D. Four
Explanation: "The explanation for this question will be added soon!".
Correct answer: Four333. Blood transport of CO2 occurs in three forms. The correct percentages of CO2 in these forms are:
- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: "The explanation for this question will be added soon!".
Correct answer: Option A- A. O2 concentration is high and CO2 is low.
- B. O2 concentration is low and CO2 is high.
- C. O2 tension is high and CO2 tension is low.
- D. O2 tension is low and CO2 tension is high.
Explanation: "The explanation for this question has been added!".
Correct answer: O2 concentration is high and CO2 is low.- A. Downward movement of diaphragm
- B. Upward movement of diaphragm
- C. Upward movement of the ribs
- D. Downward movement of the diaphragm and upward movement of ribs
Explanation: "The explanation for this question will be added soon!".
Correct answer: Downward movement of the diaphragm and upward movement of ribs336. Each bronchus on entering the lung divides and sub-divides progressively into smaller and smaller:
- A. Bronchioles
- B. Bronchi
- C. Alveolar ducts
- D. Tracheoles
Explanation: "The explanation for this question will be added soon!".
Correct answer: Bronchioles- A. With the help of RBCs and blood plasma
- B. With the help of RBCs and WBCs
- C. With the help of WBCs and blood serum
- D. With the help of platelets and corpuscles
Explanation: "The explanation for this question will be added soon!".
Correct answer: With the help of RBCs and blood plasma- A. Larynx
- B. Voicebox
- C. Vocal cords
- D. Pharynx
Explanation: "The explanation for this question will be added soon!".
Correct answer: Vocal cords- A. Bronchus
- B. Larynx
- C. Syrinx
- D. Inhalation and exhalation
Explanation: "The explanation for this question will be added soon!".
Correct answer: Larynx- A. Nasal cavity→pharynx→trachea→larynx→bronchi→bronchioles→alveoli
- B. Nasal cavity→pharynx→larynx→trachea→bronchi→bronchioles→alveoli
- C. Nasal cavity→larynx→pharynx→trachea→bronchi→bronchioles→alveoli
- D. Nasal cavity→larynx→bronchi→pharynx→trachea→bronchioles→alveoli
Explanation: "The explanation for this question will be added soon!".
Correct answer: Nasal cavity→pharynx→larynx→trachea→bronchi→bronchioles→alveoli