Living cells contain numerous enzymes that constantly scan dna, searching for damaged or incorrectly paired nucleotides. when detected, these defects are corrected by: a. ligase b. dna polymerase c. dna repair enzymes d. rna polymerase e. dna scanning enzymes

that scientist would be robert hooke

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.