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The general requirement for energy and materials is common to all living organisms. Living beings need plants and trees in order to survive, as most of their needs are met by them.
Read the passage and answer the questions.
(i) Do plants also depend on some source for food production? Explain.
(ii) How do we derive nutrition for survival? How does this nutrition vary among different organisms?
(iii) What do we learn concerning the increased cutting of trees and removal of the green cover?
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?
Only two of the following statements accurately describe what happens in the mouth.
1. Amylase breaks down large starch molecules into smaller maltose molecules.
2. Chewing increases the surface area of food for digestion
3. Saliva emulsifies fats into smaller droplets.
4. Teeth breakup large insoluble molecules into smaller soluble molecules.
Which statements are correct?