Ch-6 Life Processes (Questions) Page 101

Question 1:	What are the differences between autotrophic nutrition and heterotrophic nutrition?
Answer :
Question 2:	Where do plants get each of the raw materials required for photosynthesis?
Answer :	The following raw materials are required for photosynthesis: • The raw material CO2 enters from the atmosphere through stomata. • Water is absorbed from the soil by the plant roots. • Sunlight, an important component to manufacture food, is absorbed by the chlorophyll and other green parts of the plants.
Question 3:	What is the role of the acid in our stomach?
Answer :	The hydrochloric acid present in our stomach dissolves bits of food and creates an acidic medium. In this acidic medium, enzyme pepsinogen is converted to pepsin, which is a protein-digesting enzyme.
Question 4:	What is the function of digestive enzymes?
Answer :	Digestive enzymes such as amylase, lipase, pepsin, trypsin, etc. help in the breaking down of complex food particles into simple ones. These simple particles can be easily absorbed by the blood and thus transported to all the cells of the body.
Question 5:	How is the small intestine designed to absorb digested food?
Answer :	The small intestine has millions of tiny finger-like projections called villi. These villi increase the surface area for more efficient food absorption. Within these villi, many blood vessels are present that absorb the digested food and carry it to the blood stream. From the blood stream, the absorbed food is delivered to each and every cell of the body. Enlarged view of a villus