Question

What is not caused by a deficiency of mineral nutrition?
A. Chlorosis
B. Internode shortening
C. Necrosis
D. Etiolation

Answer 1

Hint: The word deficiency refers to the shortage or lack of a functional entity less than the normal which is required to perform a particular function. Deficiency of one more nutrition can affect the organism by causing various diseases. Mineral nutrition refers to the chemical elements required for the normal growth and functioning of the organism.

Complete answer: A condition in which the leaves of the plant turn yellow in color due to an insufficient amount of chlorophyll pigment produced by them is called chlorosis. The word chlorosis is derived from the Greek word khloros which means pale-green, greenish-yellow. The respiratory pigment chlorophyll is responsible for the green color leaves of the plant. Lack of this pigment produces leaves which are yellow, pale, or yellow-white color. Chlorosis occurs if the plant is grown in soil which lacks a deficiency of minerals like iron, magnesium, or zinc. Internode shortening in plants is caused by the deficiency of mineral nutrition and plant hormones. A form of cell injury in which premature death of cells in living tissue occurs which is caused by autolysis is called necrosis. It is caused by the deficient supply of nutrition to the cell. Etiolation refers to a process in the flowering plants which are grown in the complete absence of light or partial absence of light. The only etiolation is not caused by a deficiency of mineral nutrition
So, option D is the correct option.

Note: For the process of biosynthesis of chlorophyll, sunlight is an important requirement. Therefore, the plants which are grown in absence of sunlight will have leaves that are pale yellow in color. Etioplasts are referred to as chloroplasts which are not exposed to sunlight.