Question

q1 which shows the correct pathway for nitrification? a ammonium → nitrite → nitrate b. ammonia → nitrite → nitrate c. ammonia → nitrate → nitrite d. both a and b q2 bacteria are responsible for carrying out the process of nitrification. how are bacteria classified? a detritivores b. decomposers c. scavengers d. producers q3 why is nitrogen called a limiting nutrient? a nitrogen is very abundant in the atmosphere, but not abundant in soil b. it is easily leached out of the soil into the ground water which it pollutes c. it stays suspended in the atmosphere and cant get to the roots d. plants are mostly made of nitrogen and therefore need lots of it q4 what bacteria live in the root nodules of legumes? a denitrifying bacteria b. nitrifying bacteria c. nitrogen - fixing bacteria d. all of the above

Explanation:

Q1:

Nitrification is the process where ammonium is first oxidized to nitrite by ammonia - oxidizing bacteria, and then nitrite is oxidized to nitrate by nitrite - oxidizing bacteria. Ammonium can come from the conversion of ammonia in water.

Q2:

Bacteria involved in decomposition processes like nitrification are classified as decomposers. They break down complex organic and inorganic substances into simpler forms.

Q3:

Nitrogen is abundant in the atmosphere as $N_2$ but plants cannot directly use it in that form. In soil, its availability in a plant - usable form is limited, making it a limiting nutrient.

Q4:

Nitrogen - fixing bacteria live in the root nodules of legumes. They convert atmospheric nitrogen into a form that plants can use.

Answer:

Q1. A. Ammonium → Nitrite → Nitrate
Q2. B. Decomposers
Q3. A. Nitrogen is very abundant in the atmosphere, but not abundant in soil
Q4. C. Nitrogen - fixing bacteria