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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446 questions · page 11 of 23

  • A. Pharynx
  • B. Bronchioles
  • C. Nostrils
  • D. None of these

Explanation: Nostrils are the openings to the nasal cavities that are on the face. These air-filled pockets are connected to nasal cavities of the nose.

Correct answer: Nostrils
  • A. Contract
  • B. Increase
  • C. Decrease
  • D. Damage

Explanation: Option A: Incorrect. The muscles involved in inspiration actually contract, causing the thoracic cavity to expand.

Correct answer: Increase
  • A. Possess more RBCs with haemoglobin of low O2 binding affinity
  • B. Possess same RBCs with haemoglobin of high O2 binding affinity
  • C. Lose physical fitness to play games like football
  • D. Suffer from altitude sickness with nausea and fatigue

Explanation: When one is at a high altitude, he/she has to acclimatize to it. Breathing becomes difficult at high altitudes, because of the low density…

Correct answer: Possess more RBCs with haemoglobin of low O2 binding affinity
  • A. CO2 in air
  • B. Moisture in expired air
  • C. O2 in air
  • D. All of these

Explanation: Option A: Carbon dioxide (CO2) is a gas that is naturally present in the Earth's atmosphere.

Correct answer: Moisture in expired air
  • A. Pharynx
  • B. Bronchioles
  • C. Bronchi
  • D. Both B and C

Explanation: The pharynx is a muscular tube-shaped structure that connects the nasal cavity and mouth to the oesophagus and larynx.

Correct answer: Bronchi
  • A. 20
  • B. 30
  • C. 35
  • D. 45

Explanation: The age at which a person may develop chronic bronchitis can vary depending on various factors such as genetics, lifestyle, and exposure…

Correct answer: 45
  • A. Bronchioles
  • B. Windpipe
  • C. Bronchi
  • D. Alveoli

Explanation: Alveoli are tiny air sacs in your lungs that take up the oxygen you breathe in and keep your body going.

Correct answer: Alveoli
  • A. Lungs
  • B. Trachea
  • C. Glucagon
  • D. Bronchi

Explanation: All of the above mentioned organs are involved in breathing one way or another except glucagon

Correct answer: Glucagon
  • A. Lungs
  • B. Bronchi
  • C. Trachea
  • D. Nostrils

Explanation: Nostrils; These are the openings to the nasal cavities that are on the face. Air enters the nasal cavity through these openings

Correct answer: Nostrils
  • A. Tobacco smoking
  • B. Chemicals
  • C. Pollutants
  • D. Mutagens

Explanation: Tobacco cigarettes contain nicotine and tar which acts as a carcinogen. Carcinogens are cancer causing chemicals.

Correct answer: Tobacco smoking
  • A. Bronchi
  • B. Bronchioles
  • C. Windpipe
  • D. Larynx

Explanation: The incoming air passes from the pharynx to the larynx then to the windipe (trachea).

Correct answer: Larynx
  • A. Pleural membrane
  • B. Myocardium
  • C. Pericardium
  • D. Both Options B and C are correct

Explanation: Option A; The pleura includes two thin layers of tissue that protect and cushion the lungs.

Correct answer: Pleural membrane
  • A. Ribs
  • B. Pharynx
  • C. Lungs
  • D. Both B and C

Explanation: The ribs are supported by intercostal muscles which form the walls of the thoracic cavity and also move the ribs during breathing.

Correct answer: Ribs
  • A. Bronchioles
  • B. Bronchi
  • C. Alveoli
  • D. Air sac

Explanation: Bronchioles are approximately 1 mm or less in diameter and their walls consist of ciliated cuboidal epithelium and a layer of smooth…

Correct answer: Bronchioles
  • A. Smoking
  • B. Cough
  • C. Pollutants
  • D. Mutagens

Explanation: Smoking is the number one cause of lung cancer. It causes about 90 percent of lung cancer cases.

Correct answer: Smoking
  • A. Breakdown of glucose
  • B. Formation of ATP
  • C. Release of energy
  • D. Exchange of gases

Explanation: The oxidation-reduction processes occur inside the living cells during which organic food is broken down and energy is released.C6H12O6 +…

Correct answer: Exchange of gases
  • A. Voice box
  • B. Epiglottis
  • C. Bronchi
  • D. Wind pipe

Explanation: OPTION A: The larynx is an enlargement in the airway at the top of the trachea and below the pharynx.

Correct answer: Wind pipe
  • A. Kidney
  • B. Heart
  • C. Brain
  • D. Lungs

Explanation: Option A: The kidney is covered by a tough renal capsule. Options B : The heart is enclosed in a double membranous sac - the pericardial…

Correct answer: Lungs
  • A. 1
  • B. 2
  • C. 3
  • D. 4

Explanation: Option A is wrong because it is a fact. Each nasal cavity is not subdivided into 1 passageway.

Correct answer: 3
  • A. Air sacs
  • B. Alveoli
  • C. Bronchi
  • D. Bronchioles

Explanation: "Tiny air sacs at the end of the bronchioles (tiny branches of air tubes in the lungs).

Correct answer: Alveoli