The process of growth is determined by

The cells of plants showing frost hardness have:

The usual shape of a growth curve is:

In geometrical growth,the lag phase is represented by:

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.

The plants growing in dark show yellowing in leaves and elongated internodes, this condition is called as