Question

Which is essential for root hair growth?
(A) Zn
(B) Ca
(C) Mo
(D) S

Answer 1

There are several chemical compounds that are necessary for proper plant growth and development. Some of them are macronutrients that are highly required in the plants for functions like the proper growth of roots and shoots.

Complete answer:
Calcium(Ca) plays an important role in root hair growth in plants. It is one of the three secondary nutrients therefore and is essential for the plant to show healthy growth. It is responsible for holding the cell walls of the plants together and deficiency of Ca may cause distorted growth in some parts from improper cell wall formation, specifically in root tips, young leaves, and shoot tips. The source of calcium is mainly water and fertilizers.

Additional Information: Below are the importance of the other nutrients in plants:
Zn is also an essential element for plant development and plays a significant role in wide ranges of plant life processes. It is also a micronutrient which means it is required in lesser quantity. It is essential for the synthesis of certain proteins and is used in the formation of chlorophyll and some carbohydrates, conversion of starches to sugar, and helps the plant to withstand cold temperatures. It is also important for the formation of the Auxin hormone.
Another micronutrient, Molybdenum (Mo) is essential for the regulation of functions like conversion of inorganic phosphorus into organic forms in plants. It is a component of two enzymes that convert nitrate into nitrite and later into ammonia before plants can use it. The symbiotic nitrogen-fixing bacteria also need Mo to fix nitrogen.
Sulfur is another crucial element for plant development and it is acquired by plants from the growing medium as sulfate. It is readily soluble and subject to loss by leaching. It is an important part of all plant proteins and certain plant hormones. S is further used in the formation of some oils and volatile compounds that are found in onion and garlic.
Therefore, the correct answer is "(B) Ca".

Note: Calcium is not a mobile element within the plant therefore it relies on the transpiration process of plants. The roots take up the sap that contains Ca in it and move out to new growth where it gets used. Later the excess of Ca escapes through stomata. Some factors like High humidity, cold Temperature, etc may slow down transpiration and deficiency in Ca level. Ca deficiency can occur due to less concentration of Ca (less than 40-60ppm) in fertilizers.