The soil organisms are

Which of the following statements are incorrect?
$I.$ Hemoglobin,myoglobin,and cytochromes are iron-containing compounds.
$II.$ Copper is important for cell division in plants.
$III.$ Biotin and riboflavin are sulfur-containing vitamins.
$IV.$ Calcium is necessary for the structure of teeth and bones.
$V.$ Manganese is required in the structure of the phosphatase enzyme.

Which of the following plants is used as green manure in crop fields and in sandy soils?

The agent/s which make/s free atmospheric nitrogen available to plants is/are:

Consider the following statements regarding mineral nutrition:
$(a)$ Moderate decrease or increase of micronutrients causes deficiency and toxicity symptoms respectively.
$(b)$ Excess of manganese causes toxicity of iron, calcium and molybdenum.
$(c)$ $A$ macronutrient is said to be toxic when present below a critical concentration.
Which of the above statements are correct?

Identify the $INCORRECT$ statement regarding the role of minerals in plants.