Question

Growth of pollen tube towards embryo sac is.

• A. Phototaxis
• B. Geotropism
• C. Chemotropic
• D. Thigmotaxic

Answer 1

The correct option is C

Chemotropic

The correct option is C.

Explanation for the correct option:

1. The movement of an organism or plant in response to a chemical stimulation is known as chemotropic.
2. The development of the pollen tube towards the embryo sac exemplifies this.
3. The pollen tube does not follow a straight path to the ovary.
4. It travels towards the style's skin and curls to the bottom of the ovary, then breaks through the ovule through the micropyle and explodes into the embryo sac near the receptacle.

Explanation for the incorrect options:

Option A:

1. Phototaxis is the movement of living things toward or away from a light source (positive or negative phototaxis).
2. When exposed to light, the unicellular green alga changes its swimming path swiftly.

Option B:

1. Geotropism refers to the growth of plant components in response to the pull of gravity.
2. Negative geotropism can be seen in the upward growth of plant shoots.
3. Positive geotropism is the downward development of roots.

Option D:

Thigmotaxic is the movement of an organism towards or away from any item that gives a mechanical stimulus to the organism through physical touch or proximity.

Final answer: Growth of pollen tube towards embryo sac is Chemotropic.