In rats, the dark fur allele (D) is dominant to white fur allele (d). Two dark rats have 50 offspring listed below. 38 dark rats 12 white rats Which of the following are the genotypes of the parents? ODD x DD DD x Dd O Dd x Dd Dd x dd

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.