Name a plant which accumulates silicon.

Match the following columns correctly:

Column $I$	Column $II$
$(a)$ Boron	$(p)$ For $CO_2$ transport
$(b)$ Copper	$(q)$ Essential for nitrogen fixation
$(c)$ Molybdenum	$(r)$ Essential for sugar translocation in plants
$(d)$ Chlorine	$(s)$ Essential for chlorophyll synthesis in plants

Match the following columns:

Column-$I$	Column-$II$
$(A)$ Found in some amino acids	$(1)$ $Mg$
$(B)$ Required for photolysis of water	$(2)$ $I$
$(C)$ Not important for plants	$(3)$ $S$
$(D)$ Structural component of chlorophyll	$(4)$ $Mn$

Ammonia provided to crop plants in the form of urea is industrially fixed by . . . . . . .

Select the mismatch.

Analogy type questions:
$(1)$ Manganese toxicity : Brown spots surrounded by chlorotic veins : Molybdenum deficiency : ........
$(2)$ Conversion of nitrogen to ammonia : Nitrogen fixation : Oxidation of nitrite to nitrate : ........