Which technique is employed for the extraction and elimination of hormones?

On germination,a seed first produces shoots with leaves,and flowers appear later.
$(A)$ Why do you think this happens?
$(B)$ How is this advantageous to the plant?

Phytochrome-mediated process is:

$A$ hypothetical chemical involved in the flowering of plants is:

$A$ group of plants shows flowering in a $12$ hour day and $12$ hour night cycle. When the night phase of another group of the same plants is interrupted by a brief flash of light, flowering does not occur. In which of the following groups would you place these plants?

To induce early flowering in plants, pre-treatment of seeds or seedlings is done at . . . . . . $1-6^{\circ} C$ temperature.