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 biology digestive system oesophagus and stomach -intermediate digestion in human beings organs systems in animals

The proteolytic enzyme found in gastric juice of infants which helps in digestion of milk protein is

  1. Rennin

  2. Salivary amylase

  3. Pepsin

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

Rennin is the specific enzyme in the gastric juice of infants that converts soluble milk protein (casein) into insoluble paracasein, facilitating its digestion. Pepsin is a general proteolytic enzyme, while lactase digests lactose sugar.

Multiple choice biology digestive system oesophagus and stomach -intermediate digestion in human beings organs systems in animals

Which one of the following pairs of food compounds in humans reaches the stomach
totally undigested -

  1. Starch and cellulose

  2. Protein and starch

  3. Starch and fat

  4. Fat and cellulose
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Starch digestion begins in the mouth via salivary amylase. Proteins begin digestion in the stomach. Fats and cellulose are not significantly digested in the mouth or esophagus; therefore, they reach the stomach in a largely undigested state.

Multiple choice biology digestive system oesophagus and stomach -intermediate digestion in human beings organs systems in animals

Consider the following four statements and select the correct option stating which ones are true (T) and which ones are false (F).
(i) Salivary amylase hydrolyses proteins to amino acids.
(ii) Pancreatic amylase hydrolyses polysaccharides to disaccharides.
(iii) Enteropeptidase activates pepsinogen to pepsin.
(iv) Trypsin coagulates the milk protein casein. 

  1. T T F F

  2. F T F T

  3. F T F F

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

(i) Salivary amylase hydrolases proteins to amino acids - False

(ii) Pancreatic amylase hydrolases polysaccharides to disaccharides - True
(iii) Enteropeptidase activates pepsinogen to pepsin - False
(iv) Trypsin coagulates the milk protein casein - False
So, the correct answer is (c).

Multiple choice biology digestive system oesophagus and stomach -intermediate digestion in human beings organs systems in animals

Refer to the given flow chart.
Milk casein $\overset{Y}{\rightarrow}$ Paracasein $\overset{Z}{\rightarrow}$ Calcium paracaseinate (Curdling of milk). in it, letters 'Y' and 'Z' denote

  1. Rennin and $Ca^{++}$
  2. $Ca^{++}$ and rennin
  3. Renin, HCl and $Ca^{++}$
  4. Renin and $Ca^{++}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the digestion of milk, the enzyme rennin converts casein into paracasein. This paracasein then reacts with calcium ions (Ca++) to form insoluble calcium paracaseinate, which is the curdling process.

Multiple choice biology food through digestive tract role of large intestine in digestion busy at work - our internal organs parts of the digestive system: structure and function

Water from the undigested food is absorbed mainly in the

  1. Stomach

  2. Food pipe

  3. Small intestine

  4. Large intestine
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the digestive system.Water is absorbed here from the undigested food and the remaining waste material is stored as feces before being removed by defecation.
  • Hence water from the undigested food is absorbed mainly in the large intestine.
  • So,the correct answer is 'Large intestine'.
Multiple choice biology food through digestive tract role of large intestine in digestion busy at work - our internal organs parts of the digestive system: structure and function

Which of the following is not the function of large intestine?

  1. Absorption of water

  2. Nutrient absorption

  3. Secretion of mucus to lubricate faeces

  4. Temporary storage faeces in rectum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The 4 major functions of the large intestine are:
  • Re-absorption of water and mineral ions such as sodium and chloride.
  • Formation and temporary storage of faeces.
  • Maintaining a resident population of over 500 species of bacteria.
  • Bacterial fermentation of indigestible materials.
  •  So, the correct answer is "Nutrient absorption".
Multiple choice biology food through digestive tract role of large intestine in digestion busy at work - our internal organs parts of the digestive system: structure and function

Feces are stored in which of the following part of the body before excretion?

  1. Anus

  2. Large intestine

  3. Small intestine

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The large intestine, also called as the colon or the large bowel, is the last part of the digestive system in vertebrates. Water is absorbed here and the remaining waste material is stored as feces before being removed by defecation.

Multiple choice biology food through digestive tract role of large intestine in digestion busy at work - our internal organs parts of the digestive system: structure and function

The colon extracts .......... from solid wastes.

  1. Water

  2. Salt

  3. Both A and B

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

The colon is the last part of the digestive system in most vertebrates. It extracts water and salt from solid wastes before they are eliminated from the body and is the site in which large bacterial fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a major role in absorption of foods and nutrients. 

Multiple choice biology food through digestive tract role of large intestine in digestion busy at work - our internal organs parts of the digestive system: structure and function

The vermiform appendix is situated at the junction of

  1. Large intestine and small intestine

  2. Small intestine and duodenum

  3. Anus and rectum

  4. Stomach and duodenum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The vermiform appendix is also referred to as the vermix or the cecal appendix. It is a blind ended tube connected to the cecum, at the junction of large and small intestine. The appendix is usually located in the right lower quadrant of the abdomen, near the right hip bone.

Multiple choice biology food through digestive tract role of large intestine in digestion busy at work - our internal organs parts of the digestive system: structure and function

Where do certain symbiotic microorganisms normally occur in human body?

  1. Caecum

  2. Oral lining and tongue surface

  3. Vermiform appendix and rectum

  4. Duodenum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Caecum, a part of large intestine, is a small blind sac which hosts some symbiotic micro-organisms which helps in synthesis of Vitamin- B12 and helps in digestion
So, the correct answer is 'Caecum'
Multiple choice biology food through digestive tract role of large intestine in digestion busy at work - our internal organs parts of the digestive system: structure and function

Large intestine in man mainly carries out

  1. Absorption of water

  2. Assimilation

  3. Digestion of fats

  4. Digestion of carbohydrates
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The completely digested food in small intestine is liquid in physical state, so that, absorption of nutrients can be easily carried out but the faeces are reduced in volume and a semi-solid coherent mass because most of the water is absorbed in large intestine.

Multiple choice biology food through digestive tract role of large intestine in digestion busy at work - our internal organs parts of the digestive system: structure and function

Which is the incorrect sequence of parts in human alimentary canal?

  1. Mouth $\rightarrow$ Stomach $\rightarrow$ Small intestine $\rightarrow$ Oesophagus $\rightarrow$ Large intestine
  2. Mouth $\rightarrow$ Oesophagus $\rightarrow$ Stomach $\rightarrow$ Large intestine $\rightarrow$ Small intestine
  3. Mouth $\rightarrow$ Stomach $\rightarrow$ Oesophagus $\rightarrow$ Small intestine $\rightarrow$ Large intestine

  4. Mouth → Oesophagus → Stomach → Small intestine → Large intestine
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

After the digestion of carbohydrates in the mouth, food is passed on from mouth to stomach through the oesophagus where the digestion of proteins takes place. The food enters the small intestine for the digestion of proteins, carbohydrates and fats. Finally, it moves to the large intestine which is the last part of the alimentary canal where water is absorbed and undigested/ unabsorbed food is converted into a coherent mass of faeces and ejected from the body through a muscular anus.

Mouth $\rightarrow$ Oesophagus $\rightarrow$ Stomach $\rightarrow$ Small intestine $\rightarrow$ Large intestine

Multiple choice biology food through digestive tract role of large intestine in digestion busy at work - our internal organs parts of the digestive system: structure and function

 Find out the correct sequence for the layers in the wall of ileum from inner to outer side. 

  1. Mucosa, Circular muscles, Oblique muscles, Longitudinal muscles, Serosa

  2. Muscularis interna, Muscularis externa, Submucosa, Visceral peritoneum

  3. Mucosal epithelium, Oblique muscles, Circular muscles, Longitudinal muscles, Submucosa

  4. Mucosa, Submucosa, Muscularis externa, Circular muscles, Longitudinal muscles, Serosa
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • The ileum is the final section of the small intestine in which the remaining of the food is absorbed.  The ileum is covered with different layers as it’s structure. 

So the correct option is 'Mucosa, Submucosa, Muscularis external, circular muscles, longitudinal muscles,serosa'.
Multiple choice biology food through digestive tract role of large intestine in digestion busy at work - our internal organs parts of the digestive system: structure and function

Which of the following portion of intestine is blind sac?

  1. Caecum

  2. Anus

  3. Colon

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

The caecum is an intraperitoneal pouch which is considered to be the beginning of the large intestine. It receives chyme from ileum and connects to the ascending colon of the large intestine. The caecum is called blind sac because caecum looks like a sac which has sphincter at the ileocaecal junction and it remains closed and is invisible. Hence, it is called a blind sac.

So, the correct answer is 'Caecum'.