How is pepsinogen changed into pepsin? State its role in digestion.

How pepsinogen is converted into pepsin in stomach?

Flame cells play a role in digestion.

Answer brief : (i) Why are villi present in the intestine and not in stomach? (ii) How does pepsinogen change into its active form? (iii) What are the basic layers of the wall of alimentary canal? (iv) How does bile help in digestion of fat?

Answer briefly: (a) Why are villi present in the intestine and not in the stomach? (b) How does pepsinogen change into its active form? (c) What are the basic layers of the wall of alimentary canal? (d) How does bile help in the digestion of fats?

How many enzymes are present in pancreatic juice? Name and mention their role in digestion.

Assertion : Rhabdome is present in Palaemon. Reason : Rhabdome has an important role in digestion.