Which cells of the islets of Langerhans secrete insulin?
Correct answer D. Beta cells
Subject / 1,067 questions
MDCAT Biology MCQs
Page 10 of MDCAT Biology multiple-choice questions with answers. Tap an option to check yourself.
Page 10 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
Bile and pancreatic juice are both delivered into which part of the alimentary canal?
Correct answer D. Duodenum
Which is the longest part of the human small intestine?
Correct answer D. Ileum
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After absorption into a villus, where do most fatty acids and glycerol go?
Correct answer A. Into the lacteal, as chylomicrons
Absorbed glucose and amino acids are carried first to which organ?
Correct answer D. Liver
Which enzymes act on the brush border of the small intestinal epithelium?
Correct answer A. Maltase, sucrase, lactase and peptidases
Lactose intolerance is caused by a deficiency of which enzyme?
Correct answer A. Lactase
What is the main function of the colon?
Correct answer A. Absorption of water and mineral salts
The vermiform appendix arises from which part of the gut?
Correct answer C. Caecum
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Why can severe diarrhoea be dangerous, especially in children?
Correct answer D. Large losses of water and salts cause dehydration
In what form is the largest proportion of carbon dioxide transported in the blood?
Correct answer D. As hydrogencarbonate (bicarbonate) ions in plasma
Which enzyme in red blood cells speeds up the reaction CO₂ + H₂O → H₂CO₃?
Correct answer C. Carbonic anhydrase
What is the chloride shift in red blood cells?
Correct answer D. Movement of Cl⁻ ions into red cells as HCO₃⁻ ions diffuse out
How does a higher carbon dioxide concentration in respiring tissues affect the oxygen dissociation curve?
Correct answer D. It shifts the curve to the right, so haemoglobin releases oxygen more readily
Why is the oxygen dissociation curve of haemoglobin S-shaped (sigmoid)?
Correct answer B. Binding of one oxygen molecule makes it easier for the next ones to bind
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Compared with adult haemoglobin, where does the oxygen dissociation curve of fetal haemoglobin lie?
Correct answer A. To the left, because fetal haemoglobin has a higher affinity for oxygen
Myoglobin in muscle releases its oxygen only when partial pressure of oxygen becomes very low. What does this show?
Correct answer A. Myoglobin has a higher affinity for oxygen than haemoglobin
Why is carbon monoxide from car exhaust and cigarette smoke dangerous?
Correct answer D. It forms stable carboxyhaemoglobin and reduces the oxygen-carrying capacity of blood
How does a rise in body temperature, as in exercising muscle, affect haemoglobin?
Correct answer C. Its affinity for oxygen decreases and the dissociation curve shifts right
Where is the main respiratory centre that controls the rhythm of breathing?
Correct answer B. Medulla oblongata