Mention the site of photosynthesis. List basic requirements for this process to occur.

Which part of the alimentary canal receives bile from the liver?

$(a)$ Name the hormone which is released into the blood when its sugar level rises. Name the organ which produces this hormone and its effect on blood sugar level. Also,mention the digestive enzymes secreted by this organ with one function of each.
$(b)$ Explain the need for chemical communication in multicellular organisms.

$(a)$ How many chambers are present in the heart of $(i)$ fish $(ii)$ amphibians? $(b)$ Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?

State whether the following statement is true or false: 'Reptiles have a three-chambered heart,mammals have a four-chambered heart,and fishes have a two-chambered heart.'

“All plants give out oxygen during day and carbon dioxide during night”. Do you agree with this statement? Give reason.