The growth period of a plant is generally divided into how many phases?

What is a $Phytotron$?

Which of the following statements are correct regarding the conditions necessary for plant growth?
i. Microelements and macroelements are required for the proper growth of the plant.
ii. For proper growth of plant,optimum temperature ranges between $15^{\circ} C-25^{\circ} C$.
iii. In the absence of oxygen,the process of respiration and release of energy takes place in all plants.
iv. Gravitational force decides the direction of growth of the shoot and root.
v. Light is essential for the germination of some seeds and photosynthesis.

Growth is maximum in the zone of

What type of phenomenon is the blooming of a flower from a floral bud?

Growth of an organ is defined as