Question

where do plants get the nitrogen they need to create amino acids and dna?
a plants get their nitrogen from nitrogen gas (n₂), which moves into leaves through holes called stomata.
b plants take up nitrates (no₃⁻) from the soil and convert them into ammonia (nh₃).
c nitrogen - fixing bacteria convert nitrogen gas (n₂) into ammonia (nh₃), and plants take up some of the ammonia (nh₃) through their roots.
d both b and c are correct.
e a, b, and c are all correct.

Explanation:

Plants cannot directly use nitrogen gas (\(N_2\)) from the air. Nitrogen - fixing bacteria convert \(N_2\) into ammonia (\(NH_3\)) (as in option C). Also, plants can take up nitrates (\(NO_3^-\)) from the soil (option B). Option A is incorrect because plants do not take up \(N_2\) through stomata for nitrogen - containing biomolecules like amino acids and DNA. Since both B and C are correct statements about how plants get nitrogen for creating amino acids and DNA.

Answer:

D. Both B and C are correct.