Question

Increase in the length of the plant axis is caused by

Answer 1

Answer:

Increase in girth or thickness of the axis of plant takes lace due to the activity of secondary lateral meristems like vascular cambium andcork cambium. It is called secondary growth.

Answer 2

An increase in the length of the plant axis is caused by the plant hormone called auxin

• Certain plant hormones called growth hormones are responsible for ensuring the proper growth of the plant.
• One such hormone is named auxin (derived from tryptophan) which is responsible for the growth of the length of shoot and root of the plant.
• Auxin is also responsible for other effects like plant cell elongation and the maintenance of apical dominance in the plant.
• It also inhibits lateral bud growth in pants.

Thus, an increase in the length of the plant axis is caused by the plant hormone auxin.