An element involved in the metabolism of urea is:

Which one of the following is a micro-element?

Match the following items in List-$I$ with List-$II$ and select the correct option:

List-$I$	List-$II$
$(1)$ For repair of worn-out cells	$(a)$ Phosphorus
$(2)$ In the structure of $ATP$	$(b)$ Magnesium
$(3)$ In the synthesis of $ATP$	$(c)$ Zinc
$(4)$ In the structure of myoglobin in muscles	$(d)$ Iron

With the help of examples,describe the classification of essential elements based on the function they perform.

$S$ - Statement: Sulfur is present in the structure of cysteine and methionine amino acids.
$R$ - Reason: Phosphorus does not participate in energy exchange processes.

Which of the following is a micro-element in plants?