Biology · Science General

Human Digestive System

1,953 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 minerals and vitamins nutrition and diet role of various nutrients

For the digestion of cellulose, an enzyme called cellulase is required. Some mammals lodge cellulase producing bacteria in their digestive system by offering them food and shelter. These mammals are mostly________

  1. Herbivores

  2. Carnivores

  3. Omnivores

  4. Sanguivores
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Herbivores are plant eating animals. Plants have cellulose that need an enzyme called cellulase for its digestion. Herbivores lodge have a microbial flora are obligate or facultative anaerobes that can decompose complex plant material, such as cellulose, hemicellulose, starch, and proteins. The hydrolysis of cellulose results in sugars, which are further fermented to acetate, lactate, propionate, butyrate, carbon dioxide, and methane.
So, the correct answer is 'Herbivores'.
Multiple choice biology coordination and response control of blood glucose endocrine system and hormone hormones in human reproduction

The activities of the gastrointestinal tract are under the control of 

  1. Nervous system

  2. Hormones

  3. Both A and B

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

The activities of the gastrointestinal tract are under the control of the nervous system and hormones. The sight, smell and/or the presence of food in the oral cavity can stimulate the secretion of saliva. Similarly, gastric and intestinal secretions are also stimulated by neural signals. The muscular activities of different parts of the alimentary canal can also be moderated by neural mechanisms (both local and through CNS). Hormonal control of the secretion of digestive juices is carried out by local hormones produced by the gastric and intestinal mucosa.

So, the correct option is 'Both'.

Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

Most of the digestive enzymes belong to the class of

  1. Lyases

  2. Hydrolases

  3. Oxidoreductases

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

Hydrolase enzymes break large molecules into small molecules with the help of hydrogen and hydroxyl group of water molecules. The phenomenon is known as hydrolysis. Digestive enzymes in our body help to break down macromolecules of food into smaller molecules by the process of hydrolysis. So, digestive enzymes belong to the class Hydrolases. Thus, the correct option is B.

Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

Hydrolysis of starch occurs with the help of

  1. Sucrase

  2. Amylase

  3. Peptidase

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

Starch is used as food reserves in plants. It is a polymer of glucose. It is formed by the attachment of glucose unit by glycosidic bonds. The basic formula of starch is (C$ _6$H$ _{10}$O$ _5$)n. 

Amylase is an enzyme which helps in the digestion of the starch. It acts on the glycosidic bonds of the starch and converts into simpler compounds. It helps in the hydrolysis of this bond. It is present in the saliva and the pancreas secretion in humans and helps in intracellular digestion of starch.
So, the correct answer is option B.

Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

Name the hormone that stimulate the secretion of gastric juice.

  1. Renin

  2. Enterokinase

  3. Enterogastrone

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

Gastrin is a peptide hormone, which is secreted by the gastric glands in the stomach wall. The gastrin stimulates secretion of gastric juice rich in pepsin and hydrochloric acid. The stimulation for secretion of gastrin is presence of peptides derived from dietary proteins.

Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

Enzyme amylase belongs to category 

  1. Oxidoreductases

  2. Transferases

  3. Hydrolases

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

An amylase is an enzyme that catalyses the hydrolysis of starch into sugars. A hydrolase or hydrolytic enzyme is an enzyme that catalyzes the hydrolysis of a chemical bond. So, the correct answer is option C.

Multiple choice bio-chemistry digestion liver functions of the liver secretory organs

Cells of the liver manufacture

  1. Diastase

  2. Amylase

  3. Lipase

  4. Insulin

  5. None of the above
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The liver doesn't secrete any enzyme. The liver only secretes bile that it produced by the byproducts of haemoglobin breakdown. With the presence of bile, lipase, an enzyme will be able to break down the fat into smaller units. 

Multiple choice bio-chemistry digestion liver functions of the liver secretory organs

Read the following statements regarding liver:-
(A)Hepatic lobules are structural and functional unit of liver.
(B)Liver secreates bile, which contains digestive enzymes
(C) Each hepatic lobule is covered by a thin epithetial tissue, called "Glisson's capsule"
(D) Hepato-pancreatic duct is guarded by sphincter of Boyden.
Correct statements regarding liver is/are:-

  1. One

  2. Two

  3. Three

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

A. The functional unit of liver is called hepatic lobules. 

B. Bile is produced by the liver, which helps in the digestion of lipids in the small intestine.
C. The external surface of the liver is covered by the capsule called the Glisson's capsule.
D. The Hepato pancreatic duct is guarded by the Sphincter of Oddi.

Options A and B are correct.

Multiple choice bio-chemistry digestion liver functions of the liver secretory organs

Cells of liver which act as phagocytes are

  1. Dieters cells

  2. Kupffer cells

  3. Hensen cells

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

Kupffer cells, also known as Browicz-Kupffer cells are specialized macrophages located in the liver lining the walls of the sinusoids that form part of the reticuloendothelial system. Red blood cells are broken down by phagocytic action of Kupffer cells, where the hemoglobin molecule is split. The globin chains are re-utilized, while the iron-containing portion, heme, is further broken down into iron, which is re-utilized, and bilirubin, which is conjugated to glucuronic acid within hepatocytes and secreted into the bile.

Multiple choice bio-chemistry digestion liver functions of the liver secretory organs

Specific cells found in liver are

  1. Alpha cells

  2. Beta cells

  3. Kupffer cells

  4. Islets of Langerhans
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Kupffer cells, also known as Browicz-Kupffer cells are specialized macrophages located in the liver lining the walls of the sinusoids that form part of the reticuloendothelial system. 

Multiple choice bio-chemistry digestion liver functions of the liver secretory organs

Liver is called the reticular gland because

  1. The shape is reticular

  2. It contains reticular tissue

  3. Lobules branches and anastomose with one another to form a network

  4. Hepatic duct and cystic duct unite to form the bile duct
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • The liver is an organ that is present on the right side of the stomach.
  • Liver tissue is made up of lots of smaller units of liver cells called lobules. Many canals carrying blood and bile run between the liver cells. 
  •  Reticular fibre is a type of fibre in connective tissue. It is composed of type III collagen secreted by reticular cells. Reticular fibres crosslink to form a fine meshwork(reticulin). 
  • This network acts as a supporting mesh in soft tissue such as liver, bone marrow and the tissues and organs of the lymphatic system. Hence, the Liver is called the reticular gland because it contains reticular tissue.
So, the correct answer is 'It contains reticular tissue'.

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

If $A=$ hepatic duct, $B=$common bile duct, $C=$hepato-pancreatic duct and $D=$cystic duct, then which of the following will not be having concentrated bile juice?

  1. A

  2. B

  3. C

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

Bile is produced in the liver and then it's concentrated in the gallbladder. From gallbladder, it goes through the cystic duct. Cystic duct joins the pancreatic duct to form the hepato-pancreatic duct. Pancreatic juice and bile juice together is secreted through a common hepatic duct into the duodenum. During secretion from the hepato-pancreatic duct, pancreatic juice is present too making bile juice diluted. 

So, the correct option is 'C'.

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

Cholesterol is synthesized in

  1. Pancreas

  2. Brunners gland

  3. Spleen

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

Steroids like cholesterol are crystallisable lipids having four hydrocarbon rings, consisting of three cyclohexane and one cyclopentane ring and a long hydrocarbon side chain. In animals,  liver is the major site of cholesterol production. Cholesterol is an important constituent of bile produced in liver.

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

The organ in human body where glycogenolysis takes place is

  1. Skeletal muscles

  2. Liver

  3. Small intestine

  4. Kidney
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

The main centre of carbohydrate metabolism is liver. Following steps are related with carbohydrate metabolism-
(i) Glycogenesis- The conversion and storage of extra amount of glucose into glycogen. The main stored food in the liver is glycogen.
(ii) Glycogenolysis- The conversion of glycogen into glucose back when glucose level in blood falls down is called glycogenolysis.
(iii) Gluconeogenesis- At the time of need, liver converts non carbohydrate compounds (e.g., amino acids, fatty acids) into glucose. This conversion is called as gluconeogenesis. This is the neo-formative process of glucose. 

Glycogenolysis also takes place in the skeletal muscles during muscular excercise.