Biology is the study of life – but there is no simple definition of life. How do we recognize living things from non-living things? need correct answer Group of answer choices 1. Only living things evolve. 2. We recognize living things by their shared features such as energy transformation or reproduction. 3. Only living things have DNA. 4. Only living things contain water.

2. We recognize living things by their shared features such as energy transformation or reproduction.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.