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 food for health fats fats and their test different nutrients in food

Emulsified fats are digested by

  1. Gastric juice and pancreatic juice

  2. Pancreatic and intestinal juices

  3. Pancreatic and bile juices

  4. Bile and intestinal juices
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Emulsified fats are primarily digested in the small intestine by pancreatic lipase and intestinal lipase, which break them down into absorbable components.

Multiple choice biology food for health fats fats and their test different nutrients in food

Which of the following plays a key role in absorption and distribution of fats?

  1. Lacteals

  2. Villi

  3. Secretin

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

Meats, dairy products, seeds, nuts and oils contain dietary fat which needs to be broken down to be absorbed by the system. While the bile contains bile salts that emulsifies and pancreatic lipase acts to break lipids, to be absorbed in the blood stream this goes through further breakdown process in the small intestine where lacteals found in the villi of the intestinal wall help the lipids to pass through the  lymphatic system.

Therefore, the correct answer is option A.

Multiple choice biology food for health fats fats and their test different nutrients in food

Which of the following plays a key role in absorption and distribution of fats?

  1. Lacteals

  2. Villi

  3. Secretin

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

Lipids are fat-like molecule that cannot dissolve in water. When these reach the small intestine, the enzymes present there responsible for fat digestion acts on it. The pancreatic lipase breaks lipids down, resulting in free fatty acids and monoglycerides. Further, these are resynthesized into triglycerides which enter the lymphatic capillaries and lacteals present as the finger-like projections of the villi these acts on the lipids so as to be absorbed before they enter the bloodstream. 

Multiple choice botany know the plant world closely diversity in plants types of nutrition in plants different modes of nutrition in plants

The enzyme commonly presents in insectivorous plants to fulfil the need of their specific habit

  1. Trypsin

  2. Pepsin

  3. Pectinase

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

  • Trypsin is working as a digestive enzyme to break down proteins in the small intestine.
  • Some plants eat insects. Such plants are called insectivorous plants. They trap and digest insects. The insect is then digested by the enzyme pepsin secreted by the cells of the plants. Example -The protease secreted in the pitcher fluid is pepsin-like.
  • Pectinase is the enzyme that breaks down pectin and polysaccharides found in plant cell walls.
  • Cellulase is the enzyme that converts cellulose into glucose or a disaccharide.

So option B is correct.

Multiple choice botany know the plant world closely diversity in plants types of nutrition in plants different modes of nutrition in plants

In which of the following groups of organisms, food material is broken down outside the body and absorbed?

  1. Mushroom, Green plants, Amoeba

  2. Yeast, Mushroom, Bread mould

  3. Paramecium, Amoeba, Cuscuta

  4. Cuscuta, Lice, Tapeworm
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The green plant is photoautotrophs that synthesise food material from simple inorganic compounds like water and carbon dioxide in the presence of sunlight. 
Nutrition in Amoeba and Paramecium is holozoic. Thus, solid food particles are ingested which are then acted upon by enzymes and digested. Cuscuta, lice, and tapeworm are parasites with the heterotrophic nutritional mode. Yeast, mushroom and bread mould have a saprophytic mode of nutrition which is chemoheterotrophic in nature. They break down complex organic substances by secreting digestive enzymes outside their body and absorb simple molecules as nutrients. So, the correct answer is option B.  

Multiple choice properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

What is common among amylase, renin and trypsin?

  1. These are all proteins

  2. These are proteolytic enzymes

  3. These are produced in stomach

  4. These act at a pH lower than 7
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Amylase is a protein-based enzyme that is secreted by the salivary glands of mouth and is involved in the breakdown of starch. It functions in a neutral pH (pH 7). Renin is also a protein enzyme secreted in the stomach and involved in the coagulation of milk. It functions in a acidic pH. Trypsin is also a protein enzyme that is produced in the small intestine and is a proteolytic enzyme. It also functions in acidic pH. So, the correct answer is 'These are all proteins'.

Multiple choice properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

Many enzymes are secreted in inactive form to protect

  1. Cell proteins

  2. Mitochondria

  3. Cell membrane

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

The enzymes are protein in nature and they are generally produced in inactive form so to protect the intracellular damage of protein. For example,  digestive enzymes are secreted in form of zymogens which remains inactive in the cells in which it is produced. The active sites are blocked by the peptide which keeps the enzyme in the inactive stage so the other proteins do not get harmed by the reaction. Cleavage of this peptide cleaves activates the enzyme.

So, the correct answer is option A. 

Multiple choice properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

Read the following statement
(i) The enzymes acts on 'N' terminal of a polypeptide chain is present in A
(ii) The enzymes in 'C' terminal of a polypeptide chain is present in BChoose the option which correctly fills up the blanks
A and B

  1. Gastric juice Pancreatic juice

  2. Pancreatic juice Gastric juice

  3. Pancreatic juice Succus entericus

  4. Intestine juice Pancreatic Juice
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The Pancreatic juice containing carboxypeptidases cleave the amino acid from the peptides from the carboxyl-terminal or C terminal.
The aminopeptidases present in the succus entericus cleave the amino acid from the amino-terminal or the N-terminal.

So, the correct answer is 'Pancreatic juice Succus entericus'

Multiple choice properties of enzyme enzyme properties enzymes biomolecules: chemical constituents of living cells biology

The hydrolytic enzymes acting at low pH are

  1. $\alpha$-amylases

  2. Hydrolases

  3. Proteases

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

A protease (also called peptidase or proteinase) is any enzyme that performs proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein. Proteases may be classified by the optimal pH in which they are active: acid proteases or neutral proteases or basic proteases.

Multiple choice biology nervous system of man divisions of nervous system autonomic nervous system the human brain

Sight of delicious food usually makes mouth watery, it is a

  1. Hormonal response

  2. Neural response

  3. Optic response

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

The sense of smell and sight of food are governed by olfactory and optic responses which work together to initiate the neural response during cephalic phase of digestion. Sight, smell and sense of food initiate the neural response in which central nervous system prepares the stomach to receive food. The responses include salivation and secretion of gastric juices. This makes options C and D incorrect and option B correct. The ingestion of food stimulates the hormonal responses to food which includes endocrine system to ensure releases of various digestive hormones at appropriate time. Correct answer is B.

Multiple choice biology nervous system of man divisions of nervous system autonomic nervous system the human brain

Production of gastro-intestinal secretions and movement soon after ingestion of food are brought about by

  1. Central nervous system

  2. Sympathetic nervous system

  3. Parasympathetic nervous system

  4. Peripheral nervous system
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The parasympathetic nervous system promotes digestive activities, including gastrointestinal secretions and peristalsis, following the ingestion of food.

Multiple choice biology windows of knowledge human tongue organ of taste tongue : the organ of taste

Chemicals that stimulates taste receptor cells are called as

  1. Dorsum

  2. Tastant

  3. Saliva

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

The chemicals or the substances which can stimulate the taste receptor cells are known as tastants. The upper surface contains papillae. There are several taste receptors on the papillae. When the tastants gets dissolved in the saliva, the taste can be detected by the taste receptors.

Thus, the correct answer is option B.