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 12 of 23

  • A. 10 to 15 times per minute
  • B. 10 to 20 times per minute
  • C. 80 to 120 times per minute
  • D. 30-40 times per minute

Explanation: When you exercise and your muscles work harder, your body uses more oxygen and produces more carbon dioxide.

Correct answer: 30-40 times per minute
  • A. Alveoli
  • B. Diaphragm
  • C. Epithelial membrane
  • D. Pleura

Explanation: D is correct becauseThe lungs are surrounded by a thin double-layered membrane known as the Pleural membrane.

Correct answer: Pleura
  • A. 2
  • B. 3
  • C. 4
  • D. 5

Explanation: Option A is the correct option because There are two different types of bronchitis, acute and chronic.

Correct answer: 2
  • A. 15-20 times per minute
  • B. 30 times per minute
  • C. 20 times per minute
  • D. 10-20 times per minute

Explanation: When you exercise and your muscles work harder, your body uses more oxygen and produces more carbon dioxide.

Correct answer: 30 times per minute
  • A. Emphysema
  • B. Asthma
  • C. Pneumonia
  • D. Bronchitis

Explanation: All off these symptoms are usually of bronchitis Symptoms of emphysema are frequent coughing or wheezing or cough that produces a lot of…

Correct answer: Bronchitis
  • A. Bronchi
  • B. Bronchioles
  • C. Pharynx
  • D. Alveolar duct

Explanation: the main airways (bronchi) branch off into smaller and smaller passageways - the smallest, called bronchioles.

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

Explanation: The part of the respiratory system that has the thinnest wallwal and also the smallest diameter is bronchiole.

Correct answer: Bronchioles
  • A. Collapsing
  • B. Vibrating
  • C. Swelling
  • D. Breaking

Explanation: C-shaped cartilaginous rings reinforces the anterior and lateral sides of the trachea to protect and maintain the airway open.

Correct answer: Collapsing
  • A. Voice box
  • B. Bronchioles
  • C. Vocal cords
  • D. Vocal duct

Explanation: The vocal folds, also known as vocal cords, are located within the larynx at the top of the trachea.

Correct answer: Vocal cords
  • A. No effect on surface tension
  • B. Increasing surface tension
  • C. Decreasing surface tension
  • D. None of these

Explanation: Pulmonary surfactant is essential for life as it lines the alveoli to lower surface tension, thereby preventing atelectasis during…

Correct answer: Decreasing surface tension
  • A. Alveoli
  • B. Trachea
  • C. Diaphragm
  • D. Bronchi

Explanation: Alveoli are tiny ball-shaped air sacs which inflate and deflate, and thus, make the lungs spongy.

Correct answer: Alveoli
  • A. Shoot apex of mature stem
  • B. Embryo of the seed
  • C. Leaves of the plants
  • D. All of these

Explanation: Whenever vernalization occurs in the mature plants, the receptor of stimulus is the stem apex and embryo tips.

Correct answer: Leaves of the plants
  • A. 3
  • B. 2
  • C. 5
  • D. 6

Explanation: The two types of bronchitis are acute and chronic bronchitis.

Correct answer: 2
  • A. Intercostal muscles are contracted
  • B. Ribs are relaxed
  • C. Muscles of the diaphragm are relaxed
  • D. Lungs are relaxed

Explanation: When the lungs exhale, the diaphragm relaxes, and the volume of the thoracic cavity decreases, while the pressure within it increases.

Correct answer: Lungs are relaxed
  • A. HCl
  • B. Mucus
  • C. Enzymes
  • D. Amylase

Explanation: Goblet cells are unicellular glands that are present in the lining of the respiratory and digestive tracts.

Correct answer: Mucus
  • A. Hemoglobin
  • B. Myoglobin
  • C. Myosin
  • D. Actinomyosin

Explanation: Myoglobin is a protein present in muscles, which has one oxygen-binding site, and its function is to supply muscles constantly with oxygen.

Correct answer: Myoglobin
  • A. 6.7 litres
  • B. 2.5 litres
  • C. 7 litres
  • D. 5 litres

Explanation: In an adult human being when the lungs are fully inflated the total inside capacity of lungs is about 5 litres. (PTB)

Correct answer: 5 litres
  • A. Bronchioles
  • B. Trachea
  • C. Alveolar Sacs
  • D. Alveoli

Explanation: The site for gaseous exchange is the alveoli. Inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide…

Correct answer: Alveoli
  • A. Asthma
  • B. Emphysema
  • C. Tuberculosis
  • D. Cancer

Explanation: In emphysema, the inner walls of the air sacs are damaged, causing them to eventually rupture.

Correct answer: Emphysema
  • A. 4%
  • B. 0.04%
  • C. 0.4%
  • D. 0.0045%

Explanation: Exhaled air contains 4.4% carbon dioxide.

Correct answer: 4%