Biology · Science General

Human Digestive System

2,002 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 bio-chemistry digestive system of human absorption mechanism absorption digestion

The villi present on the wall of the small intestine

  1. Secretes digestive enzyme

  2. Increase surface area for absorption

  3. Hold mucus to protect wall

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation


  • Villi present in small intestine increase intestinal absorptive surface area providing efficient absorption of nutrients in lumen.
  • Mucosa is an innermost layer of tissues seen in the small intestine and is a mucous membrane that secretes digestive enzymes and hormones.
  • A submucosa layer provides blood vessels, nerves and lymphatic vessels to support mucosa on the surface to protect the wall.
So the correct answer is 'Increase surface area for absorption'.

Multiple choice bio-chemistry digestive system of human absorption mechanism absorption digestion

Absorption of nutrients
Read the following four statements (i) - (iv) with certain mistakes in two of them.
(i) Fructose is generally absorbed by simple diffusion.
(ii) The digestive wastes, solidified into coherent faeces in the rectum initiate an endocrinal action causing an urge or desire for its removal.
(iii) The food mixes thoroughly with the acidic gastric juke of the stomach by the churning movements of its muscular wall and is called the chyme.
(iv) The secretions of the brush border cells of the mucosa alongwith the secretions of the goblet cells constitute the succus entericus.
Which of the above two statements have mistakes?

  1. (i) and (ii)

  2. (ii) and (iii)

  3. (iii) and (iv)

  4. (i) and (iii)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Statement (i) is incorrect because fructose is absorbed by facilitated diffusion, not simple diffusion. Statement (ii) is incorrect because the urge for defecation is initiated by stretch receptors in the rectal wall, not an endocrinal action.

Multiple choice bio-chemistry digestive system of human absorption mechanism absorption digestion

The absorption of glycerol, fatty acids and monoglycerides takes place by the

  1. Wall of the stomach

  2. Lymph vessels within the villi

  3. Capillaries within the villi

  4. Colon
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Each villus has a network of capillaries and fine lymphatic vessels called lacteals close to its surface. The epithelial cells of the villi transport nutrients from the lumen of the intestine into these capillaries (amino acids and carbohydrates) and lacteals (lipids). The absorbed substances are transported via the blood vessels to different organs of the body, where they are used to build complex substances such as the proteins required by our body. The food that remains undigested and unabsorbed passes into the large intestine.

Multiple choice bio-chemistry digestive system of human absorption mechanism absorption digestion

Which of the following nutrient is absorbed by the active absorption?

  1. Amino acids

  2. Glucose

  3. Fatty acids

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Absorption is a process by which the end products of digestion pass from the alimentary canal into the blood and lymph through intestinal mucosa. It is carried out by the passive, active and facilitated type of transport mechanism.
Active transport mechanism occurs against the concentration gradient and is involved in the absorption of amino acids, monosaccharides like glucose, and electrolytes like Na+.
So the correct answer is 'Both A and B'.
Multiple choice bio-chemistry digestive system of human absorption mechanism absorption digestion

Fats are mostly absorbed in

  1. Duodenum

  2. Jejunum

  3. Ileum

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The small intestine is the main site for absorption of nutrients and digestion of fat. Fats are consist of glycerol and fatty acids. They are mostly absorbed in duodenum and jejunum part of the small intestine. Duodenum is the upper portion of the intestine that gives hormonal signal whereas jejunum has microvilli that help in increasing the surface area for the absorption of fats.
So the correct answer is 'Both A and B'.
Multiple choice biology chemical coordination and integration kidney hormones coordination in human beings- chemical control endocrine system in humans

Which one of the following is incorrectly matched?

  1. Renin- Liver

  2. Ptyalin- Mouth

  3. Pepsin- Stomach

  4. Trypsin- Intestine
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • Renin, also known as an angiotensinogenase, is an aspartic protease protein.
  • This enzyme is secreted by the kidneys that participate in the body's renin–angiotensin–aldosterone system (RAAS)  that mediates the volume of extracellular fluid (blood plasma, lymph and interstitial fluid), and arterial vasoconstriction. 
  • Thus, it regulates the body's mean arterial blood pressure. Hence, renin is not secreted by the liver.
So, the correct answer is 'Renin- Liver'.

Multiple choice biology chemical coordination and integration kidney hormones coordination in human beings- chemical control endocrine system in humans

Renin is produced by 

  1. Liver

  2. Spleen

  3. Juxtaglomerular cells

  4. Stomach
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
A. Liver is the organ of digestive system that secretes bile juice.
B. Spleen is a organ of immune system which produces blood cells.
C. Juxtaglomerular cells are granular cells of kidneys which produce renin enzyme. 
D. Stomach is the part of digestive system that stores food and secrete gastric juices.
So, the correct answer is 'Juxtaglomerular cells'.
Multiple choice biology chemical coordination and integration kidney hormones coordination in human beings- chemical control endocrine system in humans

Chymase is a

  1. Rennin

  2. Activator of prorennin

  3. Activator of chymotrypsinogen

  4. Gastric juice
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Chymase is a chymotrypsin-like serine protease found in the mast cells and also present in basophil granulocytes.
  • Chymase hydrolyzes chymotryptic substrates by activating chymotrypsinogen.
  • So, the correct answer is 'Activator of chymotrypsinogen'.
Multiple choice zoology respiratory system experiments on photosynthesis cellular respiration introduction to respiration

Useful energy is provided to living beings by the process of 

  1. Digestion

  2. Respiration

  3. Regulation

  4. Reproduction
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Respiration is the process in which nutrients are converted into useful energy in a cell. It is responsible in transporting oxygen and carbon dioxide between cells and the external environment.

Multiple choice biology control and coordination in living organisms feedback mechanism mechanism of hormone action and feedback mechanisms role of hormones in coordination

Which part of the intestine is connected to the Pancreas?

  1. Jejunum

  2. Ilem

  3. Duodenum

  4. Islets of Langerhans
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Pancreas is about 6 inches long and sits across the back of the abdomen, behind the stomach. The head of the pancreas is on the right side of the abdomen and is connected to the duodenum (the first section of the small intestine) through a small tube called the pancreatic duct.

Multiple choice biology control and coordination in living organisms feedback mechanism mechanism of hormone action and feedback mechanisms role of hormones in coordination

Which cells of the Pancreas helps in conversion of Glycogen to Glucose?

  1. Alpha Cells

  2. Beta Cells

  3. Gamma Cells

  4. Delta Cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The pancreas releases glucagon, which is produced by Alpha cells of Pancreas, when the concentration of insulin (and indirectly glucose) in the bloodstream falls too low. Glucagon causes the liver to convert stored glycogen into glucose, which is released into the bloodstream.

Multiple choice biology the endocrine system feedback mechanism mechanism of hormone action and feedback mechanisms role of hormones in coordination

Which illustrates feed back in development

  1. As tissue 'X' develops, it secretes enzyme to inhibit development of tissue 'Y'

  2. As tissue 'X' develops, it secretes something that induces tissue 'Y' to develop

  3. As tissue 'X' develops, it secretes something that slows down growth of tissue 'Y'

  4. Tissue 'X' secretes RNA which changes the development of tissue 'Y'.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The X and Y tissue system is observed in Crustaceans. The X organ produces hormones that control development, to prevent molting during development it releases an antiecdysis hormone, which stops the Y organ from secreting the molting hormone.
Therefore, the correct answer is' As tissue 'X' develops, it secretes enzyme to inhibit development of tissue 'Y'
Multiple choice common health problem international health bodies health organisation biology

Blood in stools + watery constituency of stools is found in a condition known as 

  1. Diarrhoea

  2. Indigestion

  3. Dysentery

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

Dysentery is an intestinal infection that causes severe diarrhoea with blood and mucus may be found in the stool. In diarrhea, Loose, watery stools along with abdominal cramps occur. Other symptoms of dysentery include abdominal cramps or pain, nausea, vomiting, dehydration, and fever.

So the correct answer is 'Dysentery'.

Multiple choice bio-chemistry coordination in life processes role of intestine digestion in intestine mechanism of digestion

Ammonia formed during digestion is processed in

  1. Liver

  2. Small intestine

  3. Large intestine

  4. Stomach
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • During digestion, the deamination of amino acids results in the production of ammonia (NH3). 
  • However, the liver contains a system of carrier molecules and enzymes which quickly converts the ammonia (and carbon dioxide) into urea
  • This ammonia is an extremely toxic base and its accumulation in the body may cause death.  Hence,  Ammonia is formed during digestion in the liver.
So, the correct answer is 'liver'.