Kidneys are located in the thoracic cavity, one on either side of the backbone.

In which of the following groups of organisms, food material is broken down outside the body and absorbed?

$(a)$ State the reason for the following:
$(i)$ Herbivores need a longer small intestine,while carnivores have a shorter small intestine.
$(ii)$ The lungs in human beings are designed to maximize the area for the exchange of gases.
$(b)$ The rate of breathing in aquatic organisms is much faster than that seen in terrestrial organisms.

$(a)$ 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

$(a)$ Name the extensively coiled structure of the alimentary canal.
$(b)$ Compare the length of the small intestine in herbivores and carnivores.

Name the reserved food of plant cell.