$A$ trace element is an element which

Choose the correct group of essential elements that act as components of biomolecules and are thus structural elements of cells.

Framework elements in plants are:

Which one of the following is not an essential mineral element for plants while the remaining three are?

Which one of the following is $NOT$ an essential mineral element for plants?

An element must be considered essential,when
$I.$ the element is necessary for supporting normal growth and reproduction of the plants
$II.$ the deficiency of that particular element can not be met by supplying some other element
$III.$ the element is directly involved in the metabolism of the plants. Choose the correct pair