ANIMAL NUTRITION (Digestive system)

Short answer type 

questions

Q1. Name two bile pigments. 

Ans. Biliveridin and bilirubin. 

Q2. Name two enzymes which take part in the digestion of proteins in our body. 

Ans. Pepsin, Trypsin. 

Q3. How is fat digested in the humans? 

Ans. By the activity of the enzymes lipases. 

Q4. State one function of each of the following in human body:

i) Vitamin A 

ii) Vitamin C

iii) Vitamin D

iv) Vitamin K

Ans. i) Vitamin A: Controla normal epithelial structure and growth; essential

for the formation of the visual pigment rhodospin, which aids night vision. 

ii) Vitamin C: Concerned with the metabolism of connective tissue and the production of strong skin, essential for collagen synthesis. 

iii) Vitamin D: Controls calcium and phosphorus metabolism, important in bone and tooth formation. 

iv) Vitamin K:Essential for prothrombin synthesis in the liver, a necessary factor for the blood-clotting mechanism. 

Q5. State the one importance and one deficiency symptom of the following in our body:

i) Folic acid

ii) Phosphorus

Ans. i) Folic acid:Formation of red blood corpuscles, synthesis of nucleoprotein;Anaemia- particularly in women during pregnancy. 

ii) Phosphorus: An important constituent of bone;soft bones. 

Q6. Mention the most significant function/role of microvilli. 

Ans. Microvilli, are small processes on the free surface of the intestinal cells. They increase surface area for absorption of food. 

Q7. Name the enzymes of small intestine, which catalyze the hydrolysis of carbohydrates. 

Ans. Maltase, sucrase, lactase

Q8. Define the terms digestion and assimilation. 

Ans. The process by which the complex food materials are changed to simple molecules is called digestion. 

Assimilation is the utilisation of the absorbed molecules by the body to provide either energy or materials to be incorporated into the body. 

Q9. Name the location of:

i) crypts of Lieberkuhn;

ii) Kuffer cells. 

Ans. i) Small intestine

ii) Liver. 

Q10. Mention the most significant function/role of rennin. 

Ans. Rennin is a milk coagulating enzyme, found in the gastric juice of human beings. It helps in the digestion of milk proteins. 

Q11. Name the nutrients whose deficiencies cause the following diseases in humans:

i) Pernicious anaemia- Vitamin B12

ii) Pellagra- Niacin

iii) Night blindness- Vitamin A

iv) Goitre- Iodine

v) Kwashiorkor- Proteins

Q12. Give the exact location and function of the following:

a) Epiglottis- Epiglottis is the covering of glottis in the laryngopharynx. During swalloring, it covers the glottis and prevents entry of food in the respiratory passage. 

b) Parotid gland -Parotid gland is present just below and in front of the ears. It secretes saliva. 

Q13. What is assimilation? 

Ans. Assimilation is the utilisation of absorbed food material by the living organism for the process of growth, reproduction or repair. 

Q14. Mention the most significant function of lacteals. 

Ans. Digested fats are absorbed into lacteals and transported to the bloodstream. 

Q15. Name the chemical substance that changes pepsinogen into its active form. 

Ans. HCL

Q16. What is rennin? 

Ans. It is a milk protein coagulating enzyme, also known as chymosin. 

Q17. What is the function of caecum in herbivores? 

Ans. The caecum is herbivores contains bacteria, which digest cellulose. 

Q18. What is the function of bile? 

Ans. It makes the medium alkaline and also emulsifies the fat, converting it to small oil droplets. 

Q19. Name the vitamin associated with clotting of blood. 

Ans. Vitamin K

Q20. What is the role of HCL in protein digestion? 

Ans. a) HCL converts inactive pepsinogen to pepsin. 

b) It provides acidic medium necessary for protease activity. 

c) It kills harmful bacteria. 

Q21. Why are proteases generally released in inactive form? 

Ans. If proteases are in active form and there is no food, these proteases will start digesting the cellular and extracelluar proteins of the intestinal walls thus, damaging it. Thus, they are released in inactive form. 

Q22. HCL is secreted by the parietal cell of the stomach wall. Why does it not digest the stomach wall? 

Ans. It does not digest the stomach wall because the stomach was secretes mucus, a bicarbonate rich secretion which is alkaline in nature, that helps in protecting the stomach lining from HCL. The gastric juice present in stomach also helps in neutralizing the acidity

 of HCL. 

Q23. Name the lymphatic vessel present in the villi of the small intestine. 

Ans. Lacteals

Q24. What is microvilli? State their function. 

Ans. Microvilli are minute, microscopic, bristle like projections from the absorptive cells of the intestine. They increases the surface area for absorption of nutrients. 

Q25. Name the cell that secretes mucus. What are the functions of mucus? 

Ans. Mucus is secreted by goblet cells present in the mucosal epithelium of the cell. The functions of mucus are as follows:

a) it acts as a lubricant. 

b) it protects the epithelial surface from digestive action. 

Q26. What are crypts of Leiberkuhn? 

Ans. In the intestine, the epithelium invaginates into the submucosa of the gastrointestinal tract forming pits or crypts. The pits contain gland cells, which secrete digestive juices and are called crypts of Leiberkuhn. 

Q27. What is peristalsis? How does it help in digestion? 

Ans. Peristalsis movements are wave-like contractions and relaxations of the wall of alimentary canal that pass towards the anus. There movements carry the food and the secretions of digestive glands the anus and in the process help in digestion. 

Q28. Name the secretions of goblet cells and parietal cells in human stomach. 

Ans. Goblet cells-Mucus

        Parietal cells-HCL

Q29. Give two functions of pancreas. 

Ans. The pancreas has both exocrine and endocrine functions:

a) Exocrine function: It includes secretion of pancreatic juice. 

b) Endocrine functions: It includes secretion of insulin and glucagon. 

Q30. Mention any two structural features of the small intestine, which add to its absorptive capacity. 

Ans. The two structural features are:

a) Presence of villi

b) Absorptive cells of surface epithelium possess microvilli. 

Q31. Name the human organ that has extensive power of regeneration. 

Ans. Liver

Q32. What is the function of enzyme enterokinase? 

Ans. The enzyme enterokinase converts inactive trypsinogen to trypsin, which in turn converts chymotrypsinogen to chymotrypsin and procarboxypeptidase to carboxypeptidase. 

Q33.What is PEM? What is its cause in human? 

Ans. PEM is Protein Energy Malnutrition. It is caused due to deficiency of proteins as well as lack of energy foods. 

Q34. How does saliva function in the body's defence system? 

Ans. Saliva has an enzyme lysozyme which kills bacteria. 

Q35. What carbohydrate is not digested by man? 

Ans. Cellulose. 

Q36.Name the nutrients whose deficiency causes kwashiorkor and goitre in humans. 

Ans. i) Kwashiorkor is caused by deficiency of protein

ii) Goitre is caused by deficiency of iodine. 

Q37. Mention one significant difference between in the following:

i) intracellular digestion and extracellular digestion

ii) renin and rennin

Ans.i) 

    Intracellular                    Extracellular

        Digestion                        Digestion

A type of digestion that occurs within  the cells in food  vacuoles, e.g. Amoeba  ii)    Renin The enzyme present in the kidney, which increases the uptake of sodium ions in kidney tubules.

A type of digestion that occurs outside the cells in the cavity of the alimentary canal, e.g., higher animals.      Rennin The enzyme present in gastric juice, which changes milk-protein casein to paracasein.