How do leaves of plants help in excretion?

In which of the following vertebrate group/groups,heart does not pump oxygenated blood to different parts of the body?

During respiration,exchange of gases takes place in:

$(a)$ Name the protein-digesting enzyme present in pancreatic juice and the hormone secreted by the pancreas.
$(b)$ What is the function of pancreatic juice?

Choose the function of the pancreatic juice from the following:

During the respiration of an organism $A$,one molecule of glucose produces two $ATP$ molecules,whereas in the respiration of another organism $B$,one molecule of glucose produces $38$ $ATP$ molecules.
$(a)$ Which organism is undergoing aerobic respiration?
$(b)$ Which organism is undergoing anaerobic respiration?
$(c)$ Which type of organism,$A$ or $B$,can convert glucose into alcohol?
$(d)$ Name one organism which behaves like $A$.
$(e)$ Name two organisms which behave like $B$.