(i) A substance that initiates an immune response.   (ii) A fluid that transports fatty acid and glycerol.   (iii) The structure in which the testes are present in a man.   (iv) The micro-organism that causes AIDS.   (v) The valve present in between the chambers of the right side of the human heart.   (vi) Condition of a cell placed in hypotonic solution.   (vii) A pollutant largely responsible for acid rain.   (viii) The part of the human brain that controls body temperature.