Biology · Science General

Human Digestive System

1,953 Questions

The human digestive system explores the breakdown of biomacromolecules, covering organs from the stomach to the small intestine. It involves physiological processes like chyme movement, pH levels, and nutrient absorption in the gut. These fundamental biology concepts are regularly featured in medical and general science competitive exams.

Small intestine functionsBiomacromolecule breakdownStomach and digestionIntestinal bacteria

Human Digestive System Questions

Multiple choice

Enzyme present in the saliva is

  1. pepsin

  2. lipase

  3. ptyalin

  4. renin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ptyalin, also known as salivary amylase, is the primary enzyme present in human saliva that helps break down starches into simpler sugars. Pepsin is found in the stomach, lipase is in pancreatic and gastric juices, and renin is also found in the stomach.

Multiple choice

Bile ducts carry bile from

  1. liver and gall bladder to duodenum

  2. duodenum to liver

  3. pancreas to liver

  4. stomach to liver
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bile ducts carry bile from liver and gall bladder to duodenum.

Multiple choice

The enzyme pepsin is secreted by which organ?

  1. Large intestine

  2. Pancreas

  3. Stomach

  4. Liver
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pepsin is an enzyme that breaks down proteins into smaller peptides. It is produced in the stomach and is one of the main digestive enzymes in the digestive system.

Multiple choice

Which of the following statements about saliva is not correct?

  1. Saliva contains a digestive enzyme called salivary amylase.

  2. It gives rise to germs that cause tooth decay.

  3. It dissolves some food particles to stimulate taste buds.

  4. It moistens and lubricates food to help in swallowing.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Statement b is not correct as saliva destroys the germs that cause tooth decay.

Multiple choice

The enzyme trypsin is found in

  1. intestinal juice

  2. gastric juice

  3. pancreatic juice

  4. bile
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Trypsin is secreted as the inactive proenzyme called trypsinogen which is converted into active trypsin by the enzyme intestinal enteropeptidase.

Multiple choice

Where does most of the absorption of digested food take place?

  1. Buccal cavity

  2. Stomach

  3. Small intestine

  4. Large intestine
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Most of the digested foodstuffs are absorbed in the small intestine. The digestion is completed here and the final products of digestion such as glucose, fructose, fatty acids, glycerol and amino acids are absorbed through the mucosa into the blood stream and lymph. To increase the absorptive surface area, a number of villi are found in the small intestine.