1. ‘All elements that are present in a plant need not be essential to its survival’. Comment
A plant tends to accumulate a variety of mineral elements. Out of these elements, not all of them are essential for the survival of plants. For example, the plants which grow near radioactive sites, accumulate radioactive elements are not essential for survival. Similarly, some plants can accumulate elements like gold, selenium etc. are also not essential for the survival of the plant. Hence, the importance of any element to the survival of a plant is dependent on its role in the physiology and metabolism of the plant. If an element does not have an important role to play in plant physiology, then it is not essential for survival, and if it has a role in plant physiology then it is essential for survival. Thus, all elements that are present in a plant need not be essential for its survival.