(a) (i) Give a biological molecule that contains: 1. nitrogen 2. phosphorous (ii) Describe the role of microorganisms in producing nitrates from the remains of dead organims.

(i) 1. amino acid 2. DNA(ii) Decomposer microrganisms break down dead material into ammonia. Ammonia is then converted into nitrite and then oxidised to nitrate by nitrifying bacteria. The process is known as nitrification.