If salivary amylase is lacking in the saliva,which of the following events in the mouth cavity will be affected?

$(a)$ Name the organs which secrete the following enzymes in the human digestive system:
$(i)$ Pepsin
$(ii)$ Salivary amylase
$(iii)$ Trypsin
$(iv)$ Lipase
$(b)$ Name the organs which perform the following functions in the human alimentary canal:
$(i)$ Absorption of digested food
$(ii)$ Absorption of water

Explain the process by which the energy requirements of autotrophic organisms are fulfilled. In which form are the unused carbohydrates stored?

The largest artery is the aorta and the largest vein is the vena cava.

How do desert plants perform the photosynthesis process even though their stomata remain closed during the daytime?

Explain the importance of soil for plant growth.