31 Years NEET Previous Year Questions: Digestion & Absorption - 2 (Old NCERT) - NEET MCQ

 Fat is mainly digested by pancreatic lipase while protein is digested  by enzymes in pancreatic juice, intestinal juice and stomach.  

When a major portion of pancreas is removed, the enzymes that typically digest fat and meat inside the intestine are also removed.

 Vitamin K is a fat soluble vitamin produced in sufficient quantity by intestinal bacteria. Vitamin B1 is a water soluble vitamin, obtained partly from intestinal bacteria and partly from diet. Vitamin D is a fat soluble sterol  synthesized in the skin, Vitamin C is obtained specially from citrus fruits.

Osteoblast are  the bone degenerating cells. Odontoblast are the special cells secreting dentine.

Vitamin A takes parts in synthesis of retinal pigments. Vitamin C functions as antioxidant. Vitamin D is required  for the absorption of calcium in the intestine.

Enterogasterone reduces digestive activity of stomach. Renin is secreted by kidney and regulates blood pressure. Enterokinase activates trypsinogen to trypsin.

Secretin  released by duodenum inhibits movements in  gastric intestinal tract. Enterogasterone inhibits digestive activity of stomach. Gastrin stimulates secretion of HCl.

Nightblindness is caused by deficiency of vitamin A. Cirrhosis is caused by inflammation of  liver cells. 

The daily dietary requirement of a moderately active adult individual is approximately 2,500 k cal.

Secretin is a digestive hormone. It is secreted by the intestinal wall in the duodenum. It is stimulated by food and the strong acid in stomach and intestine. Secretin is released into the bloodstream when hydrochloric acid passes from the stomach into the duodenum. It targets on the pancreas, secretory cells and muscles of the stomach. It is responsible for secretion of water and bicarbonate NaHCO3​. It inhibits gastric motility by inhibiting the secretion of gastrin.

Cholecystokinin is a digestive hormone which is released with secretin. It is secreted by cells of the upper small intestine (duodenum). It is stimulated by food (fatty chyme and amino acids) in the duodenum. It targets on gallbladder to contract and release bile juice into the intestine. It also targets pancreas to secrete pancreatic juice. Thus, the correct answer is option A, Duodenum.

Vitamin K is a fat soluble vitamin. It is essential for synthesis of prothrombin and other clotting factors. Deficiency of vitamin K increases clotting time resulting in prolonged bleeding.

Hepatic portal system brings venous blood directly from digestive tract, spleen pancreas and gall bladder to liver for extraction of nutrients and other metabolites by the hepatic portal vein.

Aorta arises from the left ventricle and carries oxygenated blood to all parts of the body. Posterior vena cava opens into the right atrium bringing deoxygenated blood from the lower half of the body.

After mastication , the food is converted into a small ball by rolling of the tongue known as bolus. Churning movement of the stomach brings  about  mechanical breakdown of the food into finer particles, the pulpy mass formed in stomach called chyme. In the intestine food is converted into a liquid emulsion due to completion of digestion of most of the nutrients. The liquefied food emulsion contained in small intestine is called chyle.

Vitamin A is essential for the synthesis of retinal pigment, rhodopsin. Carrot and papaya are good sources of vitamin A.

Boiled potatoes do not contain lactose; and cellulose which is present is not digested in man as he lacks cellulase. Starch is the major food component which is present in boiled potato and is broken down into maltose and isomaltose due to' salivary amylase and is hence digested. DNA is broken down into purines, pyrimidines and sugars by pancreatic nuclease (such as DNAse).

Vitamin D - Calciferol
Vitamin B₁ - Thiamine
Vitamin A - Retinol
Vitamin B₂ - Riboflavin

Proteases catalyze breakdown of proteins and amylases act upon carbohydrates.  Hydrolases catalyse hydrolysis.

Stool colour is due to the bile pigments biliverdine and bilirubin secreted by Liver. If stool colour is whitish grey that means secretion of biliveridin and bilirubin is not proper from the liver.

Main source of  Flourine: Drinking water, tea, sea food. Deficiency causes weak teeth and excess causes mottling of teeth or fluorosis.

option ( a) Vitamin B6 - Beri Beri

Explanation;-

Vitamin B6 deficiency is associated with diseases like weakened immune function, microcytic anemia, eletroencephalographic abnormalities, Dermatitis with cheilosis (scaling on the lips and cracks at the corners of the mouth) and glossitis, depression and confusion. 

Carbohydrates are basic source of energy proteins provide material for growth and development.

Deficiency of pyridoxine (Vit B6) causes dermatitis, anaemia, convulsions, nausea, vomiting and mental disorders.

Secretin released by duodenal cells inhibits movement in gastrointestinal tract. Cholecystokinin stimulates release of pancreatic enzymes. Prolactin is a hormone released by anterior pituitary. Parathormone is released by parathyroid glands. Estradiol is released by ovary and progesterone is released by corpus luteum.

Vitamins, A, D, E and K are fat soluble vitamins.