Chapter 12 – Mineral Nutrition

Which one of the following roles is not characteristic of an essential element?

• a.being a component of biomolecules
• b.changing the chemistry of soil
• c.being a structural component of energy related chemical compounds
• d.activation or inhibition of enzymes

Which one of the following statements can best explain the term critical concentration of an essential element?

• a.essential element concentration below which plant growth is retarded.
• b.essential element concentration below which plant growth becomes stunted.
• c.essential element concentration above which plant remains in the vegetative phase.
• d.none of the above

Deficiency symptoms of an element tend to appear first in young leaves. It indicates that the element is relatively immobile. Which one of the following elemental deficiency would show such symptoms?

• a.sulphur
• b.magnesium
• c.nitrogen
• d.potassium

Which one of the following symptoms is not due to manganese toxicity in plants?

• a.Calcium translocation in shoot apex is inhibited
• b.Deficiency in both Iron and Nitrogen is induced
• c.Appearance of brown spot surrounded by chlorotic veins
• d.None of the above

Reaction carried out by N2 fixing microbes include

• a.2NH3 + 3O2 2NO2– + 2H+ + 2H2O (i)
• b.2NO2- + O2 2NO3- (ii) Which of the following statements about these equations is not true a. step (i) is carried out by Nitrosomonas or Nitrococcus b. step (ii) is carried out by Nitrobacter
• c.both steps (i) and (ii) can be called nitrification
• d.bacteria carrying out these steps are usually photoautotrophs

With regard to the Biological Nitrogen Fixation by Rhizobium in association with soybean, which one of the following statement/ statements does not hold true.

• a.Nitrogenase may require oxygen for its functioning.
• b.Nitrogenase is MO- Fe protein
• c.Leg-hemoglobin is a pink coloured pigment.
• d.Nitrogenase helps to convert N2 gas into two molecules of ammonia.

Match the element with its associated functions/roles and choose the correct option among given below A. Boron i. splitting of H2O to liberate O2 during photosynthesis B. Manganese ii. needed for synthesis of auxins C. Molybdenum iii. component of nitrogenase D. Zinc iv. Pollen germination E. Iron v. component of ferredoxin Options

• a.A-i, B-ii, C-iii, D-iv, E-v
• b.A-iv, B-i, C-iii, D-ii, E-v
• c.A-iii, B-ii, C-iv, D-v, E-i
• d.A-ii, B-iii, C-v, D-i, E-iv

Plants can be grown in (Tick the incorrect option)

• a.soil with essential nutrients.
• b.water with essential nutrients.
• c.either water or soil with essential nutrients.
• d.water or soil without essential nutrients. MINERAL NUTRITION 65

What is common to Nepenthes, Utricularia and Drosera with regard to mode of nutrition?

Plants with zinc deficiency show reduced biosynthesis of _______________.

Yellowish edges appear in leaves deficient in _____________________ mineral .

Name the macronutrient which is a component of all organic compounds but is not obtained from soil.

Name one non-symbiotic nitrogen fixing prokaryote.

Rice fields produce an important greenhouse gas. Name it.

Complete the equation for reductive amination ______?______ + NH4+ + NADPH glutamate + H2O ? + NADP

Excess of Mn in soil leads to defeciency of Ca, Mg and Fe. Explain.