Question

Movement of pollen tube is an instance of ______.

Options

• Chemotropism

• Hydrotropism

• Phototropism

• None of these

Answer 1

Movement of pollen tube is an instance of chemotropism.

Explanation:

Chemotropism is the directional growth or movement of a plant part in direct response to an external chemical stimulus. Following pollination, the ovary and ovule of the flower secrete specific chemical attractants (such as calcium ions and sugars). The germinating pollen tube senses this concentration gradient and grows downward through the style toward the embryo sac, facilitating successful fertilisation.