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Practice each question, then open the answer or worked solution.
Which one of the following roles is not characteristic of an essential
element?
a. is 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
Option (b) is the answer
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
Option (a) is the answer.
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
Option (a) is the answer.
Which one of the following symptoms is not due to manganese toxicity
in plants?
a. Calcium translocation in shoot apex is inhibitedb. Deficiency in both Iron and Nitrogen is induced
c. The appearance of brown spot surrounded by chlorotic veins
d. None of the above
Option (b) is the answer.
The 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
Option (d) is the answer.
With regard to the Biological Nitrogen Fixation by Rhizobium in
association with soybean, which one of the following statement/
statements do not hold.
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.
Option (a) is the answer.
Match the element with its associated functions/roles and choose the
the correct option among given below
| A. Boron
B. Manganese C. Molybdenum D. Zinc E. Iron |
i. splitting of H2O to liberate O2 during
photosynthesis ii. needed for the synthesis of auxins iii. component of nitrogenase iv. Pollen germination 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
Option (b) is the answer.
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
Option (d) is the answer.