Which one of the following vitamins can be synthesized by bacteria inside the gut?

$A$ person had roti and dal for his lunch. Trace the changes in those during its passage through the alimentary canal. What are the various enzymatic types of glandular secretions in our gut helping digestion of food? What is the nature of end products obtained after complete digestion of food?

Correct the following statements by deleting one of the incorrect entries:
$(a)$ Goblet cells located in the intestinal mucosal epithelium secrete mucus/chymotrypsin.
$(b)$ Fats are broken down into di- and monoglycerides with the help of amylase/lipase.
$(c)$ Gastric glands of stomach mucosa have oxyntic cells/chief cells which secrete $HCl$.
$(d)$ Saliva contains enzymes that digest starch/protein.

Increase in gastro-intestinal secretion and movement after ingestion of food is mainly brought about by

$A$ healthy person eats the following diet: $5 \, gm$ raw sugar,$4 \, gm$ albumin,$10 \, gm$ pure buffalo ghee adulterated with $2 \, gm$ vegetable ghee (hydrogenated vegetable oil),and $5 \, gm$ lignin. How many calories is he likely to get?