Biology ยท 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 biology digestion and absorption liver functions of the liver secretory organs

It is not a function of liver

  1. Production of bile

  2. Glycogen storage

  3. Production of insulin

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

The liver performs many functions like bile production, glycogen storage, and detoxification. Insulin is produced by the beta cells of the islets of Langerhans in the pancreas.

Multiple choice biology digestion and absorption liver functions of the liver secretory organs

Bile juice helps in the digestion of fats due to presence of

  1. Bile salts

  2. Bile pigments

  3. Enzymes

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

Bile salts (like sodium glycocholate) lower the surface tension of fat droplets, breaking them into smaller particles to increase the surface area for lipase action.

Multiple choice biology digestion and absorption liver functions of the liver secretory organs

Consider the following statements :I. Nicotinamide (anti pellagra) occurs in milk, yeast, meat and leafy vegetables
II. Crypts of Lieberkuhn occur in liver
III. Steapsin is pancreatic amylase

  1. II and III are correct

  2. II and III are incorrect

  3. I and II are correct

  4. I and III are correct

  5. I and III are incorrect
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Nicotinamide is indeed a vitamin (B3). Crypts of Lieberkuhn are in the small intestine, not the liver. Steapsin is pancreatic lipase, not amylase. Thus, statements II and III are incorrect.

Multiple choice biology digestion and absorption liver functions of the liver secretory organs

Consider the following four statements. and select the correct option stating which ones are true (T) and which ones are false (F).
(i) The stomach has the lowest pH.
(ii) The liver contains lipid emulsifier.
(iii) Large intestine secretes many enzymes.
(iv) All proteases function in the lumen of small intestine.

  1. T F T F

  2. F T F T

  3. F F T T

  4. T T F F
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

(i) Stomach has low pH (True). (ii) Liver contains bile, which emulsifies lipids (True). (iii) Large intestine does not secrete digestive enzymes (False). (iv) Proteases function in various locations, not just the small intestine (False).

Multiple choice biology digestion and absorption liver functions of the liver secretory organs

A young infant may be feeding entirely on mother's milk which is white in colour but the stools which the infant passes out is quite yellowish. The yellow colour of stool is due to

  1. bile pigments passed through bile juice

  2. undigested milk protein casein

  3. pancreatic juice poured into duodenum

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

The yellow colour of the stools is due to the presence of bile pigments. Bile pigments are the excretory products. Bile is a bitter-tasting greenish-yellow alkaline fluid produced by the liver and stored in the gall bladder and secreted into the duodenum. It assists the digestion and absorption of fats by the action of bile salts, which chemically reduce fatty substances and decrease the surface tension of fat droplets so that they are broken down and emulsified. So, the correct answer is (a).

Multiple choice

The esophagus __________________________.

  1. tube which connects mouth to your lungs

  2. the tube which connects your stomach to your intestines

  3. the tube that connects your mouth to your heart

  4. none of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The esophagus is the muscular tube that connects the pharynx (throat) to the stomach. Since none of the specific options provided correctly describe this connection, 'none of the above' is the correct choice.

Multiple choice

What is peristalsis?

  1. the traveling of food down your intestines

  2. the energy collected in your heart

  3. a wave-like motion the body uses to push food

  4. none of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Peristalsis is the series of involuntary, wave-like muscle contractions that move food through the digestive tract, including the esophagus and intestines.

Multiple choice

Small food particles travel from here into the blood.

  1. large intestine

  2. kidney

  3. heart

  4. small intestine
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The small intestine is the primary site of nutrient absorption. Digested food particles pass through the walls of the small intestine into the bloodstream.

Multiple choice

Enzymes in your saliva change ____________________.

  1. solid food to fat

  2. oxygen to carbon dioxide

  3. salt to carbohydrates

  4. starch to sugar
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Saliva contains the enzyme amylase, which begins the chemical digestion process by breaking down complex carbohydrates like starch into simpler sugars.

Multiple choice

The stomach is an organ that __________.

  1. gets hungry

  2. feels empty

  3. stores food

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

The stomach is a muscular organ that receives food from the esophagus, stores it, and mixes it with digestive juices to begin the breakdown process.

Multiple choice

Where does digestion start?

  1. in the stomach

  2. in the mouth

  3. in the intestines

  4. in the throat
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Digestion begins in the mouth, where mechanical breakdown by teeth and chemical breakdown by saliva occur. The stomach, intestines, and throat are subsequent parts of the digestive tract.