Question

A high concentration of synthetic auxin is generally used for
a. Weed control
b. Preventing the growth of lateral buds
c. Enhancing root initiation
d. Controlling of cell enlargement

Answer 1

Hint: Synthetic auxins are the chemical compounds that have been synthesised which show the activity of auxin. Synthetic auxin is generally used for the controlling of broadleaf weeds in grass crops, pastures and industry.

Complete step by step answer:
Let’s discuss the above options and find the correct answer:
- Weed control: Synthetic auxin herbicides have been developed and are used for weed control. These herbicides generally imitate the function of auxin which is a plant growth hormone. Sometimes, they are also called growth regulators as they upset the natural hormone balance in plants. The synthetic auxins are used to control grass crops and turfgrass, especially for household use. Some synthetic auxin is also used to control certain aquatic weeds.
- Preventing the growth of lateral buds: Natural auxin prevents the growth of lateral buds by the elongation of the shoot apex and when the apical buds are removed it results in the formation of lateral bud. The common auxin that promotes stem elongation and inhibits the growth of lateral bud is Indole Acetic Acid (IAA).
- Enhancing root initiation: Auxin is the plant hormone that plays a major role in cell division and cell enlargement, cell elongation, enhancing root initiation, fruit growth, etc. When produced naturally it carries out the above mentioned successfully. Also, the control on the concentration of auxin produced is influential in its functions.
- Controlling of cell enlargement: Natural auxin is the plant hormone that helps to control the size and volume of the cell. Cell enlargement is caused by the softening of the cell wall and it also increases the permeability of membrane and respiration.
Hence, the correct option is A.

Note: The common examples of synthetic auxin are; 2,4 Dichloro phenoxy acetic acid etc. The synthetic auxin consists of benzoic acid, phenoxy carboxylic acid, etc.