The practice of subjecting seeds to low temperatures for a period of time in order to cause growth and flowering during the summer season is called:

Give scientific reasons:
$(1)$ Photoperiodism is essential for flowering in plants.
$(2)$ Abscission (leaf fall,flower fall,fruit fall) increases the vitality of plants.

It is known that some varieties of wheat are sown in autumn but are harvested around next mid-summer.
$(A)$ What could be the probable reason for this?
$(B)$ What term is used for this promotion of flowering under low temperature?
$(C)$ Which plant hormone can replace the cold treatment?

Define the following terms:
$(1)$ Development
$(2)$ Light period

Define/Explain: Vernalization.

What is the effect of temperature and light on plant growth regulators in plants?