Digestive System — Set 1
Biology · पाचन तंत्र · Questions 1–10 of 50
Which enzyme present in human saliva initiates the chemical digestion of carbohydrates?
Correct Answer: B. Salivary Amylase
Salivary amylase breaks down starch into simpler sugars like maltose. This process begins in the mouth as soon as food is chewed. It requires an optimum pH of about 6.8 to function effectively.
What is the primary role of Bile juice secreted by the liver?
Correct Answer: A. Emulsification of fats
The correct answer is 'Emulsification of fats'. Bile juice breaks down large fat globules into smaller droplets to increase the surface area for enzymes. This process is essential for the subsequent action of lipase. Although it aids digestion, bile contains no digestive enzymes itself.
In which part of the human digestive system does the maximum absorption of nutrients occur?
Correct Answer: C. Small Intestine
The small intestine has a very large surface area due to the presence of villi. These finger-like projections facilitate the efficient transfer of nutrients into the bloodstream. It is the longest part of the alimentary canal in humans.
Which acid is secreted by the gastric glands of the stomach to aid digestion?
Correct Answer: D. Hydrochloric Acid
Hydrochloric acid provides the acidic medium necessary for the activation of pepsin. it also serves to kill harmful bacteria that may enter with food. The stomach lining is protected from this acid by a thick layer of mucus.
The wave-like muscular contractions that push food along the digestive tract are called?
Correct Answer: A. Peristalsis
Peristalsis involves the involuntary contraction and relaxation of muscles in the esophagus and intestines. This motion ensures that food moves in one direction through the system. It occurs throughout the entire length of the alimentary canal.
Which of the following is a vestigial organ associated with the human digestive system?
Correct Answer: C. Vermiform Appendix
The vermiform appendix is a small tube attached to the cecum that has lost its original digestive function. In herbivorous ancestors, it likely helped in the digestion of cellulose. It can sometimes become inflamed, leading to a condition called appendicitis.
What is the function of the 'Villi' found in the small intestine?
Correct Answer: C. Increasing surface area for absorption
Villi are microscopic projections that significantly expand the internal area of the intestinal wall. This increased area allows for a much faster rate of nutrient uptake. Each villus contains a network of blood capillaries and a lymph vessel.
Which component of gastric juice is responsible for the digestion of proteins in the stomach?
Correct Answer: D. Pepsin
Pepsin is an enzyme that breaks down proteins into smaller peptides. It is secreted in an inactive form called pepsinogen to prevent damage to the stomach itself. It becomes active only in the presence of hydrochloric acid.
Which organ in the human body is responsible for the temporary storage of bile?
Correct Answer: D. Gallbladder
The gallbladder stores and concentrates bile produced by the liver until it is needed. It releases bile into the small intestine through the common bile duct. Gallstones can form here if the bile contains too much cholesterol.
The hardest substance in the human body, which covers the crown of a tooth, is?
Correct Answer: C. Enamel
Enamel is a highly mineralized tissue that protects the teeth from the wear and tear of chewing. It consists mostly of calcium phosphate in the form of hydroxyapatite. Unlike bone, enamel cannot regenerate once it is damaged.