MCQs On Digestion and Absorption: Introduction & Explanation

Answer: c. Bile juice, Pancreatic Juice

Explanation Bile juice secreted by the liver makes the food alkaline and breaks the fats molecules. Pancreatic juice secreted by the pancreas contains trypsin, lipase, amylase and nuclease. These are regulated by the hormone secretin and help in fat digestion. Hydrochloric acid is naturally produced in the stomach to help digest the food.

Answer: c. Carbohydrates

Explanation The buccal cavity has a number of teeth and a muscular tongue. Carbohydrate digestion begins in the buccal cavity. From there it reaches into the stomach through a food pipe which is known as the oesophagus. There is no digestion in the food pipe, the digestion process begins in the stomach.

Answer: a. Starch

Explanation Saliva is a watery substance that is produced in the mouth by the salivary glands. Saliva contains 98% water and the remaining 2% consists of electrolytes, mucus, etc. Saliva contains enzyme amylase that breaks starch into maltose and dextrin. Thus, the digestion of starch occurs through saliva even before it reaches the stomach.

Answer: a. To protect the lining of the stomach

Explanation Gastric mucus or mucus is a barrier of gel secreted by epithelial cells and glandular cells of the stomach wall. Mucus protects the inner lining of the stomach from hydrochloric acid. Pepsin helps in breaking down protein molecules; hydrochloric acid kills bacteria and mucus and helps in the functionality of pepsin at the same time.

Answer: b. Small Intestine

Explanation With a length of 7 metres the small intestine is the longest organ of the digestive system of the human body. Its main function is to complete the digestion of the food and absorb nutrients. Bile, Pancreatic enzymes and alkaline are some of the main contents of the small intestine.

Answer: d. Amino Acids

Explanation The correct answer is amino acids. In the digestion process, protein is converted to amino acids which are responsible for breaking down food. Amino acids are also called the building blocks of life. Glutamine and Tyrosine are some examples of amino acids. Lipid molecules are a combination of oils and fats.

Answer: c.To help our body remove undigested food

Explanation Fibre is a type of carbohydrate that keeps the digestive system of our body strong. Obese people and diabetic patients should have the proper amount of fibre in their food. Fibre is mainly found in wheat flour, bran, green leafy vegetables, fruits etc. We do not get nutrition from it but it is important for cleaning the digestive system.

Answer: c. Acidic – Alkaline

Explanation The level of pH of the mouth ranges from 6.2 to 7.6 with 6.7 being the average. In the mouth, the pH level is maintained by saliva. The normal pH of stomach fluid is 1.5 to 3.5. The pH of cerebrospinal fluid is 7 to 7.3 and the pH of urine is 4.6 to 8.

Answer: d. Large Intestine

Explanation The large intestine plays an essential role in the process of digestion. It is responsible for absorbing most of the water from the undigested food. The three prominent movements that occur in the large intestine are haustral churning, peristalsis and mass peristalsis. The large intestine then excretes the waste in the form of faeces through the anus.

Answer: b. Pancreas

Explanation The pancreas is located in the abdomen behind the stomach and is one of the most vital glands. They perform both endocrines as well as exocrine functions. It regulates blood sugar levels and aids the secretion of hormones like glucagon and insulin. They allow glucose into the blood to enter cells and provide the energy to function.