Imbibition is the displacement of one fluid by another immiscible fluid.

Metabolism will be adversely affected when the leaves are coated with wax on their upper surfaces in lotus. The reason is the upper surface is above the water and receives sunlight and air directly in contact with the atmosphere.

Zinc is required for auxin synthesis.

The ripening of fruits can be accelerated by artificial exposure of developing fruits to ethylene.

The cell sap in members of compositae has a unique chemical known as insulin.

In phosphorus deficiency, the first leaves to become yellow are mature leaves at the base.

Oxygen is never a limiting factor for photosynthesis. It means that the quantity of oxygen does not affect the rate of photosynthesis.

This option is correct. It is translocated in the form of sugar,  which on accumulating in tubers are enzymatically converted into starch.

Phytotron is a device for growing plants in controlled environment.

Oxygen was absent in the past and came into the atmosphere with the coming of the green plants on earth.

Opening and closing of stomata in angiosperms is due to changes in turgor pressure of guard cells. As the turgor pressure of the guard cells changes, the opening and closing of stomata occurs.

In photosynthesis, light energy is converted to chemical energy.

When simple sugar is formed in the leaves it is transported.

Organic substances such as sugars translocated in the phloem, can be demonstrated by ringing the stem.

Ethylene is a growth inhibitor.

Girdling of the plant is complete removal of a strip of bark (consisting of cork cambium, phloem, cambium and sometimes going into the xylem) from around the entire circumference of either a branch or trunk of a woody plant.

Gibberellins do not inhibit flowering in long day plants.

Nyctinasty is the circadian rhythmic nastic movement of higher plants in response to the onset of darkness.