Anatomical structures, including homologous, analogous, and vestigial structures, can be used as evidence for biological evolution. What are vestigial structures?

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.

instead of copying and pasting things off of tests or work done on computer which im sure you did, try and read over the question carefully

its b. greenhouse gasses trap uv rays for heat so that the plants stay alive.