Phytochrome is found in

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

Classify the following plants into Long Day Plants $(LDP)$, Short Day Plants $(SDP)$, and Day Neutral Plants $(DNP)$: Xanthium, Henbane $(Hyoscyamus \text{ } niger)$, Spinach, Rice, Strawberry, Bryophyllum, Sunflower, Tomato, Maize.

Phytochrome plays an important role in

If a plant needs $10$ hours of darkness to flower,identify the condition under which it will flower:
$I.$ $14$ hours day period
$II.$ $10$ hours dark period
$III.$ $9 \frac{1}{2}$ hours dark period
$IV.$ $9$ hours dark period
Choose the correct option:

In some plants,the cold treatment may be replaced by the application of