Question 30
Choose the forms in which most plants absorb nitrogen
(i) Proteins
(ii) Nitrates and Nitrites
(iii) Urea
(iv) Atmospheric nitrogen
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Question 30
Choose the forms in which most plants absorb nitrogen
(i) Proteins
(ii) Nitrates and Nitrites
(iii) Urea
(iv) Atmospheric nitrogen
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
(b) (ii) and (iii)
Plants absorb nitrogen from the soil in the form of nitrate, nitrite and urea. In aerobic soils where nitrification can occur, nitrate is usually the predominant form of available nitrogen that is absorbed. Plants can absorb nitrate or nitrite from the soil via their root hairs. If nitrate is absorbed, it is first reduced to nitrite ions and then ammonium ions for incorporation into amino acids, nucleic acids, and chlorophyll. Urea is readily soluble in water and is, perhaps, the cheapest among all the nitrogenous fertilizers based on per unit cost of nutrient. When applied to the soil, urea undergoes decomposition to nitrate in the presence of enzyme urease, secreted by soil microorganisms.
(b) (ii) and (iii)
Plants absorb nitrogen from the soil in the form of nitrate, nitrite and urea. In aerobic soils where nitrification can occur, nitrate is usually the predominant form of available nitrogen that is absorbed. Plants can absorb nitrate or nitrite from the soil via their root hairs. If nitrate is absorbed, it is first reduced to nitrite ions and then ammonium ions for incorporation into amino acids, nucleic acids, and chlorophyll. Urea is readily soluble in water and is, perhaps, the cheapest among all the nitrogenous fertilizers based on per unit cost of nutrient. When applied to the soil, urea undergoes decomposition to nitrate in the presence of enzyme urease, secreted by soil microorganisms.
