Question

nitrogen is one of the most important building blocks of life on earth. for plants, it’s so critical that it’s considered a macronutrient: something they require in large quantities in order to survive. even though nitrogen is the most abundant element in our atmosphere, plants can’t absorb it directly from the air. instead, when gaseous nitrogen reaches the ground, bacteria living in the soil and on the roots of plants must first convert it into a different chemical form. many of these microorganisms enjoy a symbiotic relationship with their host plants, gaining a steady supply of carbon—another crucial nutrient—in exchange for their nitrogen fixing. you can find nitrogen in just about every part of a plant, and it plays a major role in most essential functions. nitrogen is a key component of the amino acids that synthesize the proteins plants need to grow, which means it’s present in nearly all plant cells. it’s also integral to reproduction, as a plant’s seeds are made up of proteins. additionally, nitrogen comprises part of the chlorophyll, the natural compound that gives plants their green color and allows them to absorb light energy. it’s even present in the root enzymes that help plants take up water and other nutrients from the soil. which of these is true of the relationship between nitrogen and plants? choose one option a plants can absorb nitrogen directly from the atmosphere. b nitrogen is a micronutrient for plants. c nitrogen is essential to plants’ basic functioning. d plants have a parasitic relationship with nitrogen - fixing bacteria.

Explanation:

• Option A: The text says "plants can’t absorb it directly from the air", so A is false.
• Option B: The text states nitrogen is a "macronutrient" for plants, not a micronutrient, so B is false.
• Option C: The text mentions nitrogen plays a major role in most essential functions of plants (e.g., in amino acids for proteins, in chlorophyll, in root enzymes), so it is essential to plants’ basic functioning. This is correct.
• Option D: The text says the microorganisms (nitrogen - fixing bacteria) and plants have a "symbiotic relationship", not a parasitic one. Parasitic relationships involve one organism harming the other, while symbiotic here is mutual benefit. So D is false.

Answer:

C. Nitrogen is essential to plants’ basic functioning.