Q41. The primary role of hydrochloric acid in the stomach is to:
a) Break down fats
b) Neutralize food acidities
c) Activate digestive enzymes and kill bacteria
d) Absorb vitamin C
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Correct Answer: c) Activate digestive enzymes and kill bacteria
Explanation: Hydrochloric acid in the stomach serves to activate digestive enzymes, such as pepsin, and provides an acidic environment for digestion. It also helps kill bacteria and other pathogens in food, contributing to the body’s immune defense.
Q42. Which structure prevents food from entering the windpipe during swallowing?
a) Uvula
b) Epiglottis
c) Vocal cords
d) Tonsils
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Correct Answer: b) Epiglottis
Explanation: The epiglottis is a flap of tissue at the back of the throat that closes over the windpipe (trachea) during swallowing. This action prevents food and liquid from entering the respiratory tract.
Q43. The absorption of fats primarily takes place in the:
a) Stomach
b) Mouth
c) Small intestine
d) Large intestine
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Correct Answer: c) Small intestine
Explanation: The small intestine, specifically the duodenum and jejunum, is the primary site for the absorption of fats. Bile from the liver and enzymes from the pancreas help emulsify and break down fats, making them absorbable.
Q44. Which part of the digestive system has no significant digestive function but plays a role in immunity?
a) Appendix
b) Esophagus
c) Gallbladder
d) Liver
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Correct Answer: a) Appendix
Explanation: The appendix, a small pouch attached to the cecum, has no significant role in digestion. Recent research suggests it may play a role in immunity, serving as a storehouse for beneficial gut bacteria.
Q45. A high concentration of bacteria in the digestive system is found in the:
a) Stomach
b) Small intestine
c) Large intestine
d) Mouth
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Correct Answer: c) Large intestine
Explanation: The large intestine (colon) contains a high concentration of bacteria, known as gut flora or microbiota. These bacteria play crucial roles in digestion, vitamin production, and protection against harmful microorganisms.
Q46. Which enzyme is responsible for the digestion of proteins in the stomach?
a) Amylase
b) Lipase
c) Pepsin
d) Lactase
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Correct Answer: c) Pepsin
Explanation: Pepsin is the enzyme responsible for digesting proteins in the stomach. It is secreted as an inactive enzyme, pepsinogen, which is then activated by the acidic environment of the stomach to form pepsin.
Q47. Inflammation of the mucosal lining of the stomach is known as:
a) Gastritis
b) Ulcerative colitis
c) Gastroenteritis
d) Gastric reflux
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Correct Answer: a) Gastritis
Explanation: Gastritis is the inflammation of the mucosal lining of the stomach. It can be caused by various factors, including Helicobacter pylori infection, chronic stress, alcohol, certain medications, and autoimmune disorders.
Q48. What is the primary purpose of the digestive enzyme trypsin?
a) To break down fats
b) To break down carbohydrates
c) To break down proteins
d) To break down nucleic acids
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Correct Answer: c) To break down proteins
Explanation: Trypsin is a digestive enzyme produced in the pancreas and secreted into the small intestine. It plays a crucial role in protein digestion, breaking down proteins into smaller peptides.
Q49. The movement of nutrients from the digestive system into the bloodstream is known as:
a) Digestion
b) Absorption
c) Secretion
d) Excretion
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Correct Answer: b) Absorption
Explanation: Absorption is the process by which digested nutrients are taken up from the digestive tract and enter the bloodstream or lymphatic system. This process mainly occurs in the small intestine.
Q50. Which vitamin is synthesized by bacteria in the human large intestine?
a) Vitamin A
b) Vitamin B12
c) Vitamin D
d) Vitamin K
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Correct Answer: d) Vitamin K
Explanation: Vitamin K is synthesized by bacteria in the human large intestine (colon). It plays an important role in blood clotting and bone metabolism. The body can absorb some of this vitamin K for use.