Question

Reading about the digestive glands and their action, a student got confused about some facts. Given below are some questions, concerning the facts.
(i) Why cannot we digest raw green plants in our alimentary canal?
(ii) Why are digestive enzymes present in an inactive form in the body when we can require their action any time?
(iii) HCL is an acid which kills bacteria ingested with food, but does not harm the walls of stomach. Why?
(iv) What values do you think the student conveys from his questions?

Answer 1

Answer:

We are unable to digest raw green plants in our alimentary canal because they contains cellulose which we can't digest except the herbivores

Answer 2

Answer:

I. We cannot digest raw green plants(or any food) in the alimentary canal since the alimentary canal does not secretes any enzymes or juices

ii. They're present in inactive forms so as to prevent it's reaction with other cells/tissues

iii. HCl cannot harm the walls of the stomach because the walls are lined with mucous membranes which protect them from the corrosive nature of the acid

iv. The student is conveying the different facts about the digestive system, according to which our biological system works.