Question

Criteria for essentiality in mineral nutrition were first shown by
A. Arnon
B. Liebigs
C. Steward
D. Levitt

Answer 1

Hint: A plant cannot complete its life-cycle in the absence of the element. The action of the element must be specific, with no other element being able to completely substitute for it. The element must be shown to be directly involved in the nutrition of the plant. It was first shown by an American plant physiologist.

Complete step by step answer:
A. In 1939, Arnon and Stout published the criteria for the essentiality of a nutrient element. It includes:
i. The criteria are as the element must be present in the plant for normal growth and completion of the life cycle.
ii. The function of the element must not be replaceable by another mineral element.
iii. The element must be directly involved in plant metabolism.
B. Justus Freiherr von Liebig was born on 12 May 1803 and died on 18 April 1873. He was a German scientist who made major contributions to agriculture and biochemistry. He is considered as one of the principal founders of organic chemistry. As a professor at the University of Giessen, he started the modern laboratory oriented teaching method, and for such innovations, he is regarded as one of the greatest chemistry teachers of all time. He has been described as the "father of the fertilizer industry" for his emphasis on nitrogen and trace minerals as essential plant nutrients.
C. Frederick Campion steward was born in Pimlico, London but grew up in Yorkshire. He studied at Heckmondwike Grammar School and then attended the University of Leeds, where he gained a BSc in Biology in 1924 and then undertook research in the Botany department.
D. Michael Levitt, born on 9 May 1947, is a South African-born biophysicist and a professor of structural biology at Stanford University since 1987. Levitt received the Nobel Prize in Chemistry in 2013, together with Martin Karplus and Arieh Warshel, for "the development of multiscale models for complex chemical systems.
Hence, the correct answer is option A.

Note: Minerals including phosphorus, calcium, sodium, potassium, magnesium, manganese, sulfur, chloride, iron, iodine, etc. are considered essential mineral nutrients. These minerals are even found in blood, bones, tissues, of every living cell.