Question

The plant hormone that inhibits the growth is called as:
A. Cytokinins
B. Gibberellins
C. Auxins
D. Abscisic acid

Answer 1

Hint: Hormones are the chemical substances which are secreted by different parts of the plant body and these are responsible for growth and development of the plant body.

Complete answer:
There are various hormones present in the plant which are responsible for regulating different functions and processes in the plant. Abscisic acid is the hormone which inhibits the plant growth, and also it is responsible for wilting of the leaves, germination of the seed, it is responsible for stimulating the closure of stomata in the epidermis and it also helps in increasing the tolerance of the plants to various stressful situations and thus named as stress hormone. It has an antagonistic effect to that of the gibberellins.
Other hormones secreted by the plants are auxins, gibberellins, cytokinins and ethylene.
Auxins are mostly secreted at root and shoot apices, it helps in promoting the flowering for example in pineapples, prevents abscission of fruit and leaf at early stages, regulates the bending of the shoot of the plant, elongation of cells.
Cytokinins help in the cell division, it is also known for production of the new leaves, chloroplast in leaves, growth of the lateral and adventitious shoots.
Gibberellins are responsible for controlling the growth of the stem of the plant and in fruits like apple, help in elongating and improving the shape, delays senescence etc.
Ethylene is a gaseous hormone, responsible for senescence and ripening of the fruits, it is responsible for breaking seed and bud dormancy etc.

So, the correct answer is (D).

Note: Plant growth and plant inhibitor hormones are found at different places and perform specific functions. Each hormone is important for regulating the growth and development of the plant body.