Which of the following are not tropisms?

(i) growing of pollen tube in response to a sugary substance

(ii) folding up of leaves of sensitive plant in response to touch

(iii) winding of tendril around a support in response to touch

(iv) opening up of the leaves of a daisy flower in response to light

The bending of the stem of a plant towards a source of light is caused by the action of a phytohormone known as:

Which of the following plant part exhibits negative phototropism?

The chemical substance P is made and secreted by the meristematic tissue at the tip of stem (or shoot) of a plant. The chemical substance P is responsible for a phenomenon Q in plants in which the stem bends towards a source of light. The same chemical substance P has an opposite effect on the root of a plant. It causes the root of a plant to bend away from the source of light in a process called R.

(a) What is the chemical substance P?

(b) State whether P prefers to remains in the sunlight side of a stem or in shade.

(c) What is the effect of substance P on the rate of growth of (i) a root, and (ii) a stem?

(d) What is the name of process (i) Q, and (ii) R?

(e) What is the general name of chemical substances like P? Name another substance which belongs to this class of chemical substances.

A potted plant is growing in a transparent glass jar. In this plant, X and Y are the two growing parts having a lot of meristematic tissue. It is observed that the part X of this plant exhibits positive geotropism but negative phototropism. On the other hand, part Y of this plant exhibits negative geotropism but positive phototropism.

(a) Name the part X of plant.

(b) Name the part Y of plant.

(c) Which part of the plant, X or Y, will exhibit positive hydrotropism?

(d) Which part of the plant, X or Y, can have tendrils on it?