Animal Physiology: Circulation and Excretion

Organisms which excrete ammonia as main excretory product are 
State the following statement true of false:
Monocytes are granulocytes 
If the concentration of urine  decreases .......... hormone will be released.
Which part of the heart is in contracting phase ? Give reason to support your answer.
Explain the transport of oxygen and carbon dioxide in the blood?