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

In which part of the intestine are M cells found in mammals?  

  1. Interacting with intraepithelial lymphocytes.

  2. In the lamina propria

  3. In the follicles of the Peyer's patches.

  4. In the pyloric antrum

  5. In the dome area of Peyer's patches
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Peyer's patches are covered by specialszed epithelium (follicle-associated epithelium). Some of these epithelial cells have surfaces, which seem folded under the scanning electron microscope. These microfold, or M, cells sample and actively transport particulate antigens from the lumen into the ‘dome’ area, where priming of both T and B lymphocytes occurs.

Multiple choice

Carbohydrates are one of the main types of nutrients and the most important source of energy for our body. Which of the following statements regarding the digestion of carbohydrates in the human gut is FALSE?

  1. The monsaccharides are absorbed by active transport.

  2. The plant fibres are passed through the digestive system as fibre.

  3. Pancreatic amylase digests all the remaining starch in the oesophagus.

  4. Salivary amylase starts the digestion of starch.

  5. The ileum enzymes attached to the epithelial cells complete the digestion of disaccharides to monosaccharides.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pancreatic amylase digests all the remaining starch in the duodenum. Amylase digests starch molecules from the ends of the chains in two-glucose units, forming the disaccharide maltose. Glycogen is also digested here.

Multiple choice

The process of removing waste material (feces) from the digestive tract is known as defaecation. The substance accelerating the process of defaecation is

  1. laxatives

  2. cathartic

  3. tegaserod

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

Cathartic is a substance that accelerates defecation. This is in contrast to a laxative, which is a substance which eases defecation, usually by softening feces. It is possible for a substance to be both a laxative and a cathartic. However, agents such as psyllium seed husks increase the bulk of the feces.

Multiple choice

Which of the following enzymes cleaves amyloid precursor protein in its transmembrane region?

  1. Alpha secretases

  2. Amino acid permeases

  3. Carnitine-acylcarnitine translocases

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

Alpha secretases are a family of proteolytic enzymes that cleave amyloid precursor protein (APP) in its transmembrane region. Specifically, alpha secretases cleave within the fragment that gives rise to the Alzheimer's disease-associated peptide amyloid beta when APP is instead processed by beta secretase and gamma secretase.

Multiple choice

The enzyme pepsin converts

  1. carbohydrates to sugar

  2. proteins to amino acids

  3. proteins to peptones

  4. fats of fatty acids to glycerol

  5. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pepsin is a stomach enzyme that breaks down proteins into smaller peptides (peptones) during digestion.

Multiple choice

Bile is stored and concentrated by

  1. the pancreas

  2. the gall bladder

  3. the liver

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

It stores and concentrates bile, and then releases it into the duodenum to help absorb and digest fats.

Multiple choice

Which of the following organs secretes a strong acid and powerful enzymes for the breakdown process of food?

  1. Mouth

  2. Esophagus

  3. Stomach

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

The stomach is a hollow organ, or container, that holds food while it is being mixed with enzymes that continue the process of breaking down food into a usable form. Cells in the lining of the stomach secrete a strong acid and powerful enzymes that are responsible for the breakdown process. When the contents of the stomach are sufficiently processed, they are released into the small intestine.

Multiple choice

Which among the following is an organ of lower gastrointestinal tract?

  1. Mouth

  2. Pharynx

  3. Large intestine

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

Large intestine is divided into three parts. The first organ of the large intestine is the cecum. The cecum is attached to the appendix and is also the connecting pouch between the small and the large intestines. The colon comes after the cecum and is responsible for the abrogation of water and salts from the digested foods. The third part of the large intestine is the rectum, which acts as the connection between the intestines and anus.It is an organ of lower gastrointestinal tract .

Multiple choice

Enzyme present in human saliva is

  1. Chymotrypsinogen

  2. Trypsinogen

  3. Pancreatic lipase

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

Salivary amylase (ptyalin) is an enzyme that catalyses the breakdown of starch into sugars. Amylase is present in human saliva, where it begins the chemical process of digestion.

Multiple choice

What term is applied to partially digested food?

  1. Chyme

  2. Bolus

  3. Mucus

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

Chyme is the semifluid mass of partly digested food expelled by the stomach into the duodenum. In other words, chyme is partially digested food.

Multiple choice

The processes like digestion,lacrimation, and micturition are controlled by

  1. the parasympathetic nervous system

  2. the central nervous system

  3. the peripheral nervous system

  4. the sympathetic nervous system

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

The parasympathetic system specifically is responsible for stimulation of rest-and-digest activities that occur when the body is at rest  including sexual arousal, salivation, lacrimation (tears), urination, digestion and defecation.

Multiple choice

Which among the following is a part of the large intestine?

  1. Definitive urogenital sinus

  2. Uterus

  3. Rectum

  4. Prostate

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

The rectum is the final straight portion of the large intestine in some mammals and the gut in others, terminating in the anus. The human rectum is about 12 cm long.

Multiple choice

Lysosomal enzymes work efficiently inside the lysosome because they

  1. work best at basic pH

  2. work best at neutral pH

  3. inactivate other enzymes

  4. resist basic pH

  5. work efficiently at acidic pH
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

All lysosymal enzymes work best at acidic pH and therefore they are known as acid hydrolases. They do not work efficiently at basic pH. The inside of the lysosome is maintained at 4.8 pH with the help of special hydrogen ion pump.

Multiple choice

What happens after an onion is cut?

Directions: Read the passage and answer the question that follows.

Let’s look at it from the point of view of the onion. An onion is perfectly polite to us until we start hacking at it with a knife. Alas, the act of cutting enlivens a gas, propanethiol S-oxide, which works in tandem with the enzymes in the onion to unleash a passive sulphur compound found within the onion.
The result: as you cut, the gas moves upwards and, combined with the water in your eyes, creates sulphuric acid.
Your eyes aren’t happy, even if you are, and react in the only way they know how when irritated by a foreign substance - they start tearing. Rubbing your eyes with your hands is about the worst way to alleviate the problem, since your hands are likely full of the tear - inducing agent too. We’ve heard all kinds of folk remedies for onion tears, ranging from rubbing the onion with lemon to wearing gloves as you cut to donning scuba diving masks while performing surgery. But we’re of the old school: no pain, no gain.

  1. It becomes impolite and angry.

  2. It unleashes a passive sulphur compound.

  3. It emits sulphuric acid.

  4. It hits your eye and makes you cry.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Alas, the act of cutting enlivens a gas, propanethiol S-oxide, which works in tandem with the enzymes in the onion to unleash a passive sulphur compound found within the onion.

Multiple choice

What is the positive effect of Artificial sweeteners?

Directions: Read the passage given below and answer the question.

Bloating can be caused by a variety of factors like health issues, genetics, or medications; but it can also be caused by the foods we eat. Although we may be eating a healthy diet, some foods like broccoli and milk can cause painful gas and bloating that’s as uncomfortable as it is unsightly. Here is a list of six bloating culprits to watch out for.
Broccoli Although filled with fibre and vitamins, broccoli can also cause gas and bloating. Try eating broccoli very slowly to reduce gas.
Artificial sweeteners They may save on calories, but artificial sweeteners contain sugar alcohols which can cause bloating. Minimise your use of artificial sweeteners or skip them altogether to reduce uncomfortable gas.
Chewing gum While it may help to digest your food and keep your teeth white, chewing gum can bring excess air into your digestive system, which causes gas. Chew gum slowly to reduce gas.
Cabbage Delicious and healthy cabbage is a great vegetable to enjoy all year round. But this leafy veggie can also spur painful bloating. Avoid it or try eating it slowly for relief.
Carbonated drinks Although some popular sodas were created to help digestion, they may cause bloating as well. Limit your consumption of these bubbly treats to keep your digestive system on track.
Milk It may be filled with vitamins and nutrients, but milk is a major offender of bloating and gas. Try opting for lactose-free milk or almond milk for relief without sacrificing the milky taste.

  1. They help to cut down calories in your sweet food

  2. They have sugar alcohol content

  3. They bring excessive air into the digestive system

  4. All of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The only positive effect is the saving on calories, the rest are negative effects.