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 digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

Which one of the following statements is true regarding digestion and absorption of food in humans?

  1. Oxyntic cells in our stomach secrete the proenzyme pepsinogen
  2. Fructose and amino acids are absorbed through intestinal mucosa with the help of carrier ions like ${K}^{+}$

  3. Chylomicrons are small lipoprotein particles that are transported from the intestine through blood capillaries to various tissues.

  4. About 60% of starch is hydrolysed by salivary amylase in our mouth
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the intestinal mucosal cells, after absorption, the triglycerides and cholesterol are re-esterified to form chylomicrons. The chylomicrons in turn are secreted into intestinal lymph, enter the blood stream through the thoracic duct and bind to the wall of capillaries in adipose and skeletal tissue.

So, option C is the correct answer.

Multiple choice biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

Which one of the following statements is true regarding digestion and absorption of food on humans?

  1. Fructose and amino acids are absorbed through intestinal mucosa with the help of carrier ions like ${Na}^{+}$

  2. Chylomicrons are small lipoprotein particles that are transported from intestine into blood capillaries

  3. About 60% of starch in hydrolysed by salivary amylase in our mouth

  4. Oxyntic cells in our stomach secrete the proenzyme pepsinogen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Digestion is the process where complex material in the food is broken down to simple nutrients and molecules so that they can be absorbed and circulated in the body. 
  • The digestion of the food starts in the buccal cavity of the organism where the enzyme amylase is secreted. This enzyme is used for the digestion of the starch present in the food. Though much of the starch is digested in the mouth it is divided in disaccharide units of carbohydrates which will be further digested in intestine. 
  • The food from the buccal cavity is taken to the stomach via oesophagus where the food is stored for about 3 to 4 hours and mixed with the hydrochloric acid which is secreted by the oxyntic cell present in the mucosa wall of the stomach. This will give the food a acidic pH which is necessary for the activation of the pepsin enzyme which are there for digestion of proteins to peptides. 
  • This acidic chyme of the stomach is to be transported for further digestion in the intestine where it is mixed with the alkaline secretion released from the liver and pancreas. 
  • In intestine the food components such as carbohydrates, proteins, lipids etc are digested to small absorbable molecules. 
  • The carbohydrates are digested to monosaccharides glucose, fructose, galactose, proteins are broken down to amino acids and lipids are reduced to small fat globules called microns. 
  • Some of these components are already present in the cell fo the body surrounding the digestive track. So for the transport of molecules ion transporters are used sach as sodium ion transporter, etc. 
  • Glucose is easily digested compared to other molecules of monosaccharides as it is easily soluble in water. Monosaccharides such as fructose and amino acid units are transported to the blood stream along with the sodium ions that are transportedby the sodium ion transporter. 
  • Fat globules are transported by the lacteal cells that are present in the intestine mucosa of the intestine. Chylomicrons are also used to transport fat to liver and adipose tissue where it can be stored. 
  • Therfore for the following question option A and C are correct. 
Multiple choice biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

Rennin and lactase, the enzymes required to digest milk, disappear in the human body by the age of

  1. Five

  2. Three

  3. Two

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

Rennin is an aspartic endopeptidase belonging to MEROPS A1 family. It is produced by newborn ruminant animals in the lining of the abomasum to curdle the milk they ingest, allowing a longer residence in the bowels and better absorption. It is widely used in the production of cheese. Lactase is an enzyme produced by many organisms.  Lactase can be purchased as a food supplement, and is added to milk to produce "lactose-free" milk products. Lactase is the enzymes that splits lactose (milk sugar) into glucose and galactose. The enzymes necessary to break down and digest milk (rennin and lactase) are all gone by the age of three in most humans. 

So the correct option is 'three'.

Multiple choice biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

Which of the following processes is helped by bile salts?

  1. Nucleic acid $\overset{Nuclease}{\rightarrow}$ Nucleotides $\overset{Nucleotidase}{\rightarrow}$ Nucleosides $\overset{Nucleosidase}{\rightarrow}$ Sugars + bases
  2. Sucrose $\overset{Sucrase}{\rightarrow}$ Glucose + Fructose
  3. Fats $\overset{Lipase}{\rightarrow}$ Diglyceides $\overset{Lipase}{\rightarrow}$ Monoglycerides
  4. Proteins, peptones, proteoses $\xrightarrow[Carboxypeptidase]{Trypsin/Chymotrypsin}$ Dipeptides
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The correct answer is (c).

Multiple choice biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

The digestion of cellulose in rabbit and other herbivorous mammals takes place in

  1. Vermiform appendix

  2. Colon

  3. Caecum

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

Hindgut fermentation is a digestive process seen in monogastric herbivores, animals with a simple, single-chambered stomach. Cellulose is digested with the aid of symbiotic bacteria. The microbial fermentation occurs in the digestive organs that follow the small intestine: the large intestine and caecum.

Multiple choice biology digestion and absorption digestion in small intestine digestive glands and their secretions alimentary canal

Sucrase is an enzyme found in:-

  1. saliva

  2. gastric juice

  3. intestinal juice

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

Sucrase enzymes are located on the brush border of the small intestine. The enzymes catalyze the hydrolysis of sucrose to fructose and glucose. The sucrase enzyme invertase, which occurs more commonly in plants, also hydrolyzes sucrose but by a different mechanism

So, the correct option is 'Intestinal juice'

Multiple choice evs more about organ system introduction to excretory system structures and functions related to the excretory system introduction to excretion

Which of the following is NOT a physical process of digestion?

  1. Deglutition

  2. Churning

  3. Peristalsis

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

(A) Deglutition is the process of swallowing the masticated food.

(B) Churning is the process in which the stomach mixes its digestive enzyme with food.
(C) Peristalsis is a wave-like muscle contraction that helps in the food movement in different digestive organs like oesophagus. 
(D) Emulsification is the process of mixing of bile with fat to change it into micelles.
So, the correct option is 'Emulsification'.

Multiple choice evs more about organ system introduction to excretory system structures and functions related to the excretory system introduction to excretion

Which of the following part is excluded from the study of T.S. of gut.

  1. Pharynx

  2. Esophagus

  3. Colon

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

Esophagus, colon and rectum are studied with the T.S. of the gut. They are all a part of the digestive system where is wearing is a part of the digestive as well as the respiratory system and it is not studied along with them.

So the correct option is 'Pharynx'.

Multiple choice evs more about organ system introduction to excretory system structures and functions related to the excretory system introduction to excretion

In which organ the digestion of protein starts in the human digestive tract?

  1. Mouth

  2. Oesophagus

  3. Stomach

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

It begins in the stomach by pepsin which breaks down the peptide bind and makes protein smaller for easier digestion. Trypsin and chymotrypsin are also enzymes that are created by the pancreas and will cut down proteins into small peptides. 


So the correct option is "stomach".

Multiple choice evs more about organ system introduction to excretory system structures and functions related to the excretory system introduction to excretion

Which of these is a part of your digestive system?

  1. Stomach

  2. Pancreas

  3. Rectum

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

All of these choices are a part of your digestive system. Your digestive system has many other associated organs including the small intestine, large intestine, and liver. The stomach is an area of food digestion. The pancreas releases hormones, that affect the digestive process. The rectum is the last place you store you food before the process of elimination (pooping).

Multiple choice evs more about organ system introduction to excretory system structures and functions related to the excretory system introduction to excretion

What tube is used by both the digestive and respiratory systems?

  1. Esophagus

  2. Larynx

  3. Pharynx

  4. None of these.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The pharynx connects the mouth to an area in your throat with a flap. The flap is the epiglottis. The flap moves to one side for food and the other side as you breathe. The branching point leads to the larynx or the esophagus.

Multiple choice evs more about organ system introduction to excretory system structures and functions related to the excretory system introduction to excretion

The major parts of the digestive system of grass hopper are

  1. Gizzard, crop and hepatic caecae

  2. Foregut, midgut and hind gut

  3. Gizzard, ileum and midgut

  4. Pharynx, oesophagus and stomach
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The alimentary canal of grasshopper is divided into three main portions as

  • Foregut
  • Midgut
  • Hindgut
Foregut consists of mouth surrounded by the mouth-parts.
Midgut consists entirely of stomach or ventriculus.
Hindgut is a coiled structure consisting of anterior ileum, middle colon and posterior is rectum.
Therefore, the correct answer is option B.

Multiple choice evs more about organ system introduction to excretory system structures and functions related to the excretory system introduction to excretion

......... constitute the digestive system.

  1. The digestive tract

  2. The associated glands together

  3. Both A and B

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

The digestive system consists of the alimentary canal (digestive tract) and the associated digestive glands, which work together to process food.