Criteria for Essentiality

Q. Arnon and Stout proposed

1. Law of minimum
2. Importance of plant growth
3. Criteria for essentiality of elements
4. Active absorption of ions

Q.

‘All elements that are present in a plant need not be essential to its survival’. Comment.

Q.

Elements that have no role to play in plants have not been found to be present in plants.

1. True

2. False

Q. Which of the following is/are the criteria required for the essentiality of an element in plants?

1. The element must be directly involved in the metabolism of the plant
2. The element must be absolutely essential for growth and reproduction
3. The requirement of the element is specific and cannot be replaced by another element
4. All of these

Q.

Which of the following are the criteria for an essential element?

1. They should be absolutely necessary for supporting normal growth and reproduction of the plants.

2. The requirement of the element must be specific and not replaceable by another element.

3. Should be a structural component of energy-related chemical compounds

4. Must be directly involved in the metabolism of the plant.

Q. The functions of the essential elements overlap each other.

1. False
2. True

Q.

If cell is basic structural and functional unit of life, then life is also present on other planets or stars. Are the aliens made up of cells? Justify.

Q. Star shaped group of minerals are called as

1. Lithocyte
2. Raphides
3. Druses
4. Cystolith