Question

Nitrogen is not taken up by plants in _______ form.

(a) N2

(b) NO3^–

(c) NO2^–

(d) NH4^+

This question was addressed to me in quiz.

I'm obligated to ask this question of Mineral Requirements of a Plant-2 in division Mineral Nutrition of Biology – Class 11

Answer 1

The correct choice is (a) N2

For explanation: N2 is the form of nitrogen which exists in the atmospheric but is unavailable and is not useful for the plants. It has to be converted to other molecular forms by different nitrogen fixation processes in order to be accessible to plants. Plants mostly take up nitrogen in form of NO3^–. Also, sometimes they absorb nitrogen in NO2^– and NH4^+ forms.