Name the energy currency in the living organisms. When and where is it produced?

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

Which of the following statement$(s)$ is (are) true about respiration?
$(i)$ During inhalation,ribs move inward and diaphragm is raised
$(ii)$ In the alveoli,exchange of gases takes place i.e.,oxygen from alveolar air diffuses into blood and carbon dioxide from blood into alveolar air
$(iii)$ Haemoglobin has greater affinity for carbon dioxide than oxygen
$(iv)$ Alveoli increase surface area for exchange of gases

Choose the event that does not occur in photosynthesis.

The blood leaving the tissues becomes richer in

Explain the mechanism of photosynthesis.