Why do many premature babies suffer from respiratory distress syndrome?
Correct answer B. Their lungs have not yet produced enough surfactant
Subject / 1,067 questions
MDCAT Biology MCQs
Page 12 of MDCAT Biology multiple-choice questions with answers. Tap an option to check yourself.
Page 12 of 54
- Biological Molecules 74
- Coordination and Control 72
- Biology Diagnostic 70
- Cell Structure and Function 67
- Biotechnology 65
- Reproduction 58
- Bioenergetics 55
- Circulation 50
- Inheritance 48
- Digestion 45
- Immunity 45
- Support and Movement 45
- Acellular Life (Viruses) 45
- Homeostasis 45
- Respiration and Gaseous Exchange 45
- Evolution 45
- Enzymes 45
- Cell Cycle 41
- Chromosome and DNA 40
- Biology Introduction 38
- Ecosystem 27
Which change occurs during inspiration in humans?
Correct answer D. The diaphragm contracts and flattens
Why is normal quiet expiration described as a passive process?
Correct answer D. It depends mainly on elastic recoil of the lungs as inspiratory muscles relax
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Which muscles contract during forced expiration, for example while coughing?
Correct answer D. Internal intercostal and abdominal muscles
What is the approximate tidal volume of a resting adult human?
Correct answer B. 500 cm³
Vital capacity is the sum of which lung volumes?
Correct answer A. Tidal volume + inspiratory reserve volume + expiratory reserve volume
Which lung volume cannot be measured directly with a simple spirometer?
Correct answer D. Residual volume
A person has tidal volume 500 cm³, inspiratory reserve 3000 cm³, expiratory reserve 1100 cm³ and residual volume 1200 cm³. What is the total lung capacity?
Correct answer A. 5800 cm³
A resting adult breathes 12 times per minute with a tidal volume of 500 cm³. What is the pulmonary (minute) ventilation?
Correct answer A. 6000 cm³ per minute
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A person has tidal volume 500 cm³, anatomical dead space 150 cm³ and a breathing rate of 12 per minute. What is the alveolar ventilation?
Correct answer B. 4200 cm³ per minute
In what form is most oxygen transported in human blood?
Correct answer D. As oxyhaemoglobin in red blood cells
What is the maximum number of oxygen molecules that one haemoglobin molecule can carry?
Correct answer D. 4
Which part of the human respiratory tract is supported by C-shaped rings of cartilage?
Correct answer D. Trachea
Why are the cartilage rings of the trachea incomplete at the back?
Correct answer B. To allow the oesophagus behind it to expand when food is swallowed
What is the function of the epiglottis?
Correct answer A. To cover the entrance of the larynx during swallowing
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In severe combined immunodeficiency (SCID), which cells are defective?
Correct answer A. Both B and T lymphocytes
Why are immunosuppressive drugs such as ciclosporin given after organ transplantation?
Correct answer A. To reduce T cell attack on the foreign tissue antigens of the graft
According to clonal selection, what happens when an antigen enters the body?
Correct answer A. It activates only lymphocytes with complementary receptors, which then divide by mitosis
Cell-mediated immunity is especially important against which of the following?
Correct answer B. Virus-infected cells and cancer cells
When antibodies bind several bacteria together into clumps, what is this process called?
Correct answer D. Agglutination