NEET BIOLOGY

Detailed explanation-1: -Movement of plants in response to chemical stimuli is called chemotropism. E.g. Growth of pollen tube towards the ovary in response to the chemicals produced by the ovary. Whereas geotropic movement is a movement in response to the gravitational force of earth. Hydrotropism is movement in response to moisture.

Detailed explanation-2: -Chemotropism-Chemo-tropism is the growth of plants, navigated by chemical stimulus from outside of the organism or organisms part.

Detailed explanation-3: -(iii) Growth of polen tube towards ovum is an example of chemotropism. The growth of the pollen tube toward the ovule responses to the chemicals released by the stigma.

Detailed explanation-4: -The growth of plant parts in response to a chemical stimulus is known as chemotropism. The growth of a pollen tube towards the ovule induced by a sugary stimulus is an example of chemotropism. This is an example of positive chemotropism as the pollen tube grows towards the stimulus.

Detailed explanation-5: -Plant movement in reaction to chemical stimuli is known as chemotropism. The growth response is positive chemotropism when it is directed toward the stimulus. When the growth response is away from the stimulus, it is called negative chemotropism. Example: Growth of pollen tubes towards ovules.