3
MCQ (Single Correct 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
4
MCQ (Single Correct Answer)
Which one of the following symptoms is not due to manganese toxicity in plants?
A
Calcium translocation in shoot opex is inhibit
B
Deficiency in both iron and zitrogen induced
C
Appearance of brown spot surrounded by chlorotic veins
D
None of the above
5
MCQ (Single Correct Answer)
Reaction carried out by $\mathrm{N}_2$ fixing microbes include
(a) $2 \mathrm{NH}_3+3 \mathrm{O}_2 \longrightarrow 2 \mathrm{NO}_2^{-}+2 \mathrm{H}^{+}+2 \mathrm{H}_2 \mathrm{O}$ ............ (i)
(b) $2 \mathrm{NO}_2+\mathrm{O}_2 \longrightarrow 2 \mathrm{NO}_3$ ............. (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
6
MCQ (Single Correct Answer)
With regard to the biological nitrogen fixation by Rhizobium in association with soyabean, 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-haemoglobin is a pink coloured pigment.
D
Nitrogenase helps to convert $\mathrm{N}_2$ gas into two molecules of ammonia.
7
MCQ (Single Correct Answer)
Match the element with its associated functions/roles and choose the correct option among given below
| A. | Boron | 1. | Splitting of $\mathrm{H}_2 \mathrm{O}$ to liberate $\mathrm{O}_2$ during photosynthesis |
|---|---|---|---|
| B. | Manganese | 2. | Needed for synthesis of auxins |
| C. | Molybdenum | 3. | Component of nitrogenase |
| D. | Zinc | 4. | Pollen germination |
| E. | Iron | 5. | Component of ferredoxin |
A
$1,2,3,4,5$
B
$4,1,3,2,5$
C
$3,2,4,5,1$
D
$2,3,5,1,4$