Biology ยท 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

Digestion is brought about by

  1. acids

  2. alkali

  3. enzymes

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

Digestion is a biochemical process where complex food molecules are broken down into simpler absorbable forms by the action of enzymes.

Multiple choice

Trypsin is secreted by

  1. Liver

  2. Thyroid

  3. Pancreas

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

Trypsin is a digestive enzyme secreted by the pancreas in an inactive form (trypsinogen) and activated in the small intestine to break down proteins.

Multiple choice

If we take food rich in lime juice, then

  1. action of ptyalin on starch is enhanced

  2. action of ptyalin on starch is reduced

  3. action of ptyalin on starch is unaffected

  4. action of ptyalin on starch stops
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If we take food rich in lime juice, then action of ptyalin on starch is reduced as ptyalin becomes inactive at acidic pH.

Multiple choice

Amino acids are the products of the digestion of the

  1. protein

  2. CHO

  3. fats

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

Proteins are complex molecules composed of long chains of amino acids. During digestion, enzymes break these chains down into individual amino acids for absorption.

Multiple choice

Piecemeal necrosis on liver biopsy is characteristic of

  1. chronic active hepatitis

  2. acute viral hepatitis

  3. both (1) and (2)

  4. neither (1) nor (2)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Piecemeal necrosis, also known as interface hepatitis, is a hallmark histological finding in chronic active hepatitis. It represents the destruction of hepatocytes at the limiting plate.

Multiple choice

Which of the following is not an end product of digestation?

  1. Glucose

  2. Amino Acids

  3. Fatty acids

  4. Alumina acids
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Digestion breaks down food into glucose (from carbohydrates), amino acids (from proteins), fatty acids and glycerol (from fats). 'Alumina acids' is not a recognized biological term or digestion product - it appears to be a made-up or misspelled term.

Multiple choice

Which harmone is secreted by the pancreas?

  1. Testosterone

  2. Pepsine

  3. Insuline

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

The pancreas secretes insulin, which regulates blood sugar levels, and glucagon. Testosterone is produced by testes, pepsin is a digestive enzyme from stomach, and estrogen is from ovaries. Note: 'Insuline' should be spelled 'Insulin' and 'harmone' should be 'hormone'.

Multiple choice

The substance that lubricates the food in the alimentary canal is

  1. hydrochloric acid

  2. ptylan

  3. mucin

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

Mucin is the mucus secretion that lubricates food in the alimentary canal, helping it move smoothly. Hydrochloric acid digests food, ptyalin (salivary amylase) digests starch, and pepsin digests proteins.

Multiple choice

Which of the following enzymes is/are manufactured and secreted by intestinal mucosa, but not released in the lumen of intestine?

  1. Peptidases

  2. Disaccharidases

  3. Amylases

  4. Both (1) and (2)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The epithelial cells of intestinal mucosa manufacture and secrete disaccharidases and peptidases. These enzymes are not released into the lumen of intestine but remain closely associated with the microvilli of the epithelial cells.