Identify the mismatched pair.

Which of the following bacteria is associated with nitrogen fixation?

Name a plant which accumulates silicon.

Match the columns:
$I$ $II$
$(A)$ Magnesium $(i)$ Found in middle lamella
$(B)$ Sulphur $(ii)$ $A$ structural component of chlorophyll
$(C)$ Calcium $(iii)$ Required for enzyme activity
$(D)$ Iodine $(iv)$ Found in some amino acids
$(E)$ Manganese $(v)$ $A$ component of sugars
$(vi)$ Not important for plants

Match the following and choose the correct combination from the options given.

Column $I$	Column $II$
$a.$ Potassium	$(i)$ Germination of pollen grains
$b.$ Molybdenum	$(ii)$ Involved in synthesis of auxin
$c.$ Boron	$(iii)$ Involved in stomatal movement
$d.$ Zinc	$(iv)$ Constituent of ferredoxin
$e.$ Sulphur	$(v)$ Component of nitrate reductase

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