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

A man cannot digest cellulose whereas cows can do so because

  1. their gut contains certain bacteria capable of digesting cellulose

  2. they have a many-chambered stomach

  3. they have efficient molars for grinding

  4. they produce an enzyme that can digest cellulose

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

   A man cannot digest cellulose whereas cows can do so because their gut contains certain bacteria capable of digesting cellulose.

Multiple choice

Which of the following food is digested easily in the human body?

  1. Sucrose

  2. Glucose

  3. Starch

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

Glucose is a monosaccharide that requires no digestion - it can be absorbed directly through the intestinal wall into the bloodstream via specific transporters. Sucrose is a disaccharide that must first be broken down by the enzyme sucrase into glucose and fructose before absorption. Starch is a polysaccharide requiring extensive enzymatic breakdown by amylase into maltose and eventually glucose. Cellulose cannot be digested by humans at all due to lack of cellulase enzyme. Therefore glucose is the most easily and rapidly absorbed.

Multiple choice

Match the following:

 
Names of cells Functions
a. Oxyntic cell 1. Its function is to secrete mucus for lubricating the food.
b. Zymogen cell 2. Its function is to secrete a proenzyme of protein digestive enzyme.
c. Mucous cell 3. Its function is to secrete hydrochloric acid and activate pepsinogen into the functional pepsin.

  1. a - 3, b - 2, c - 1

  2. a - 3, b - 1, c - 2

  3. a - 2, b - 1, c - 3

  4. a - 2, b - 3, c - 1

  5. a - 1, b - 2, c - 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option. The function of oxyntic cell is to secrete hydrochloric acid and activate pepsinogen into the functional pepsin. The function of zymogen cell is to secrete a proenzyme of protein digestive enzyme. The function of mucous cell is to secrete mucus for lubricating the food.

Multiple choice

Which of the following groups of organs belongs to digestive system?

  1. Food pipe, windpipe, stomach, mouth

  2. Food pipe, diaphragm, lungs, liver

  3. Liver, food pipe, stomach, small intestine

  4. Teeth, tongue, windpipe, stomach

  5. Food pipe, teeth, tongue, lungs
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Here all organs belong to digestive system. Food pipe helps food to reach to the stomach, liver produces bile juice that helps carry away waste and broken down fats in the small intestine during digestion.

Multiple choice

Which of the following statements is false?

  1. Lungs throw out oxygen and carbon dioxide.

  2. Sweat is excreted by the skin.

  3. Undigested food is thrown out as feces.

  4. Waste products are harmful to our body.

  5. Digestive juices make easy digestion.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Lungs belong to our respiratory system, and are responsible for breathing in and out. We breathe in oxygen, and we breathe out carbon dioxide.

Multiple choice

When we eat food our stomach expands and it contracts when food goes out. Thus the stomach can expand and contract. All this is possible because our stomach is made up of which of the following components?

  1. Blood

  2. Muscles

  3. Bones

  4. Iron

  5. Skin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Muscles are one of the crucial organs of our body. They are incredibly sophisticated and can expand and contract when they relax. Our stomach is made up of muscles, so it expands when food goes inside and it contracts when the food goes out. They are long-lasting, self-healing and are able to grow stronger with practice. They do everything from allowing us to walk to keeping our blood flowing.

Multiple choice

Which of the following statements is correct about roughage?

  1. It is easily digestible in the intestine.

  2. It is a kind of protein.

  3. After digestion, it releases energy for the body.

  4. It contains all the nutrients needed to keep body healthy.

  5. Its intake is suggested to reduce obesity.

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Intake of roughage in a diet is suggested to reduce obesity. 

Multiple choice

The gall bladder is meant for __________.

  1. storing bile

  2. concentrating bile

  3. storing and concentrating bile

  4. storing bile and producing it when needed
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The gall bladder is attached with liver and it receives bile from the liver when there is no food in the duodenum for emulsification. Thus, gall bladder stores the bile. Since gall bladder is much smaller than liver, the bile has to be concentrated for storage. Hence, (3) is correct. It should be noted that gall bladder can't produce bile.

Multiple choice

______________ are two hormones that stimulate pancreatic juice secretion.

  1. Cholecystokinin and pancreozymin

  2. Pepsin and rennin

  3. Pancreozymin and pepsin

  4. Rennin and cholecystokinin

  5. Pepsin and cholecystokinin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Correct answer. Cholecystokinin and pancreozymin are two hormones that stimulate the secretion of pancreatic juice. Cholecystokinin causes contraction of the gall bladder and discharges the bile into the duodenum. Pancreozymin also stimulates the pancreas to secrete insulin and glucagon.

Multiple choice

The lining wall of the alimentary canal appears different in different parts of the gut, reflecting different roles, but always has the same basic layers. Which among the following layers prevents food from traveling backward?

  1. The muscularis externa

  2. The gastric mucosa

  3. The submucosa

  4. The serosa

  5. The oral mucosa
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The muscularis externa consists of an inner circular layer and a longitudinal outer muscular layer.