Ratio of . . . . . . and . . . . . . plant hormones and their interactions control the morphogenic differentiation.

Thigmotropism is the response of the plant to

Plants which behave as mesophytes in rainy season and as xerophytes in summers are called:

Phytohormones control:

Read the following statements regarding $\text{PGRs}$:
$A.$ Ethylene also promotes root growth and root hair formation.
$B.$ Natural cytokinins are synthesized in regions where rapid cell division occurs.
$C.$ $2,4-D$,widely used to kill monocotyledonous weeds,does not affect mature dicotyledonous plants.

The physiologically active form of phytochrome is: