$SDP$ is also called:

The pigment involved in red-far red light interconversion is

Define/Explain: Long-day plants.

Write a short note on vernalisation.

At which wavelength is light absorbed by the phytochrome in the $P_r$ form (in $, nm$)?

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?