CBSE Questions for Class 11 Medical Biology Digestion And Absorption Quiz 2 - MCQExams.com

• Peyer's patches are small masses of lymphoid tissue found throughout the wall of the ileum region of the small intestine of mammals.
• It is also known as lymphoid nodules. It is an important part of the immune system which prevents the growth of antigens like pathogenic bacteria in the intestines.

• The pancreas has dual nature exocrine and endocrine, endocrine secretes hormone and exocrine secretes digestive enzymes (pancreatic juice).
• Pancreatic juice is secreted by the acinar cells of the pancreas which contains a variety of enzymes such as trypsin, chymotrypsin, amylase, lipase, carboxypeptidase.

$$\textbf{Correct answer: C}$$ 

$$\textbf{Option (A):}$$ 

$$\bullet$$ Lacteals are not found in the lymph. It is the region where the filtration of blood containing the absorbed nutrients takes place.

$$\textbf{Option (B):}$$ 

$$\bullet$$ Pancreas acts as a mixed gland as it secretes both enzymes from the exocrine part and hormones from the endocrine part.

$$\textbf{Option (C):}$$ 

$$\bullet$$ Lacteals are the central lymph vessels which are found under the villi. 

$$\bullet$$ The lacteal absorbs the digested fats from the intestine and it carries the components to the adipocyte cells in the form of a chylomicron.

$$\textbf{Option (D):}$$ 

$$\bullet$$ The spleen is the region for filtration of RBC so that only the functional and new mature RBC remains in the blood.

Hence, the correct answer is option (C).

$$\textbf{Correct option:B}$$ 

$$\textbf{Solution:}$$

$$\bullet$$ The  glands which can function as both exocrine and endocrine are known as heterocrine glands and pancreas is a heterocrine .

• Amylase is an enzyme that breaks starch down into sugar. 
• Amylase is present in human saliva, where it begins the chemical process of carbohydrate digestion. 
• In animals, it is a major digestive enzyme and its optimum pH is 6.7-7.0.

• The salivary gland is an exocrine gland in the mouth that secretes saliva to lubricate the mouth and helps in the digestion and swallowing of food.
• Humans have 3 pairs of salivary glands; the parotid, submaxillary and sublingual. 

• The pancreas secretes pancreatic juice. The pancreatic juice contains the following enzymes trypsinogen, chymotrypsinogen, procarboxypeptidases, amylases, lipases and nucleases. 
• The pH of the pancreatic juice is about 8.6(alkaline). It is alkaline because it has a high concentration of bicarbonate ions,
• So, the correct answer is '8.6'.

• Pepsinogen proenzyme is released by the chief cells in the stomach wall, and upon mixing with the hydrochloric acid of the gastric juice, pepsinogen activates to become pepsin. 
• Trypsinogen is present in the pancreas and released in significant amount when required for protein digestion. Trypsinogen is in an inactive form which is converted to active form trypsin. Hence, trypsinogen is same as pepsinogen.

• Beta cells are a type of cell in the pancreas located in the islets of Langerhans. Beta cells produce, store and release the hormone insulin. 
• Mast cells are found in connective tissue that contains numerous basophilic granules and releases substances such as heparin and histamine in response to injury or inflammation. 
• Paneth cells are a specialized type of epithelial cells found in the mucous membrane lining of the small intestine. Paneth cells secrete lysozyme, which has antimicrobial activity. 
• The pancreatic acinar cell is the functional unit of the exocrine pancreas. It synthesizes, stores, and secretes digestive enzymes.

• Protein digestion first begins in the stomach, where pepsinogen is converted to active form pepsin, by hydrochloric acid. Pepsin breaks proteins down into polypeptides. 
• Aminopeptidase, Carboxypeptidase, and Trypsin work on proteins when half-digested food enters the small intestine.
  

• Pancreatic juice is secreted by the pancreas, which contains a variety of enzymes, including trypsinogen, chymotrypsinogen, elastase, carboxypeptidase, pancreatic lipase, nucleases, and amylase. 
• A nucleotidase is a hydrolytic enzyme that is not found in human pancreatic juice. 
• It catalyzes the hydrolysis of a nucleotide into a nucleoside and a phosphate.