2. The are the "powerhouses" of the cell.
a. mitochondria
b. Golgi bodies
C. Vesicles
d. cell membranes

A. mitochondria is the powerhouse of the cell

Mitochondria

Explanation:

answer; i believe that the correct answer is(d) nondisjunction during meiosis;

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.